My question is when Job was written. I am not necessarily wondering when the events in Job took place, nor am I asking when the bulk of the content was written (in the case of redaction) -- though these things may be relevant data points. I am wondering when the book in its canonical form was written.
If there are differing opinions on this (as I'm sure there are), what are the primary arguments in each major direction?
Disclaimer and Explanation of Citations and Notations: The evidence here is largely gleaned from Protestant source material (my tradition), and is presented in a way that argues toward Job being an ancient composition (my view); but the evidence also mentions there are numerous other views on this. A bibliography of all referenced works is given, and citations are in a parenthetical form with author reference to that bibliography. Footnotes are used for additional information on topics, sometimes giving additional citations or information on the source material that the cited source is using for support.
As one commentator puts it, "there are no irrefutable clues" with respect to dating the book, such that "proposals have ranged over many centuries from before the time of Moses to the period between the testaments" (Alden, 25).1
Assuming Job was a real person (which I believe to be so, as well as most of the authors of works referenced here), it is generally believed from internal evidence that he lived roughly during the time of the patriarchs (Alden, 26).2 So the oldest it might possibly be is circa early 3rd millennium BC to late 2nd millennium BC. James Smith notes that J. Sidlow Baxter "thinks that Job might be 'the oldest book in the world,'"3 but also states, "Few modern scholars, however, would date the book as early as Moses" (Smith, ch. 2). Nevertheless, some do—Roy Zuck notes the character of the book "give[s] the impression that it was written by an eyewitness," which in his dating is patriarchal period, and "numerous features point to a single author" (Zuck, 716). And Mal Couch states the opposite of Smith regarding "majority" view (I suspect Couch is probably limiting his majority to conservative scholars),
Though some place Job as having been written during the period of Solomon (971–931 BC), the majority opinion would probably place it just before the patriarchal age.
Yet D. A. Carson et al. give the bounding range as a much narrower, more recent dating period:
We cannot put a date on the composition of the book of Job, except for the outer limits, perhaps the seventh and the second centuries BC. A folk tale of a righteous sufferer probably existed long before the present poem came into being (Carson, 460).
That is their limit of the possibility, showing they have none of their group that considers the much older dating.
In short, scholarship is deeply (and one might say broadly) divided.
Aramaic words found in Job had been leading scholars to lean "toward the end of the Old Testament period" and thus a late writing, but that has recently been challenged as unfounded grounds for late dating, since
more Aramaic inscriptions from the second millennium B.C. have come to light; the use of Aramaic may actually point to the great age of the book rather than to its lateness (Alden, 26).4
Of the Aramaisms, Spence-Jones noted that Job is
full of Aramaisms which are not of the later type, but such as characterize the antique and highly poetic style, and occur in parts of the Pentateuch, in the Song of Deborah, and in the earliest Psalms. The style has a “grand archaic character,” which has been recognized by almost all critics (Spence-Jones, xiv).
However, true Aramaisms is also in doubt, as the text may have more Arabic connections.5 2nd millennium BC dating also corresponds to Alden's statement:
observations connecting the language of Job with Ugaritic, whose mid-second millennium B.C. date argues in favor of an early Job (Alden, 27).6
Nevertheless, Alden notes some points of relation to later writings:
After Job, Psalms is the book most cross-referenced in this study [his commentary on Job]. Beyond that, one can find in Job rare words, analogous constructions, and phrases that also occur in books from Genesis to Malachi. Simply because of the nature of the material, many of these features reflect the wisdom books; and because of the size and vocabulary of Isaiah, many reflect that eighth-century prophet (Alden, 26-27).
However, Smith notes about language arguments that:
Arguments based on the alleged lateness of the language is precarious. The book may have been editorially updated from time to time. Be that as it may, the linguistic evidence is so ambiguous that some scholars have reversed the argument. The language, they say, points to an early period of Israel’s history (Smith, ch. 2.).
The subject matter by some is believed to be too developed for an early writing, but as Alden warns:
The idea should be resisted that ancient peoples were primitive and therefore incapable of thinking of or discussing the subtle issues that fill the pages of Job (Alden, 27).7
Regarding subject matter, Spence-Jones states in favor of early composition that Job has
no mention—not the faintest hint—of any of the great events of Israelite history, not even of the Exodus, the passage of the Red Sea, or the giving of the Law on Sinai, much less of the conquest of Canaan, or of the stirring times of the judges and the first great kings of Israel. It is inconceivable, as has been often said, that a writer of a late date, say of the time of Captivity, or of Josiah, or even of Solomon, should, in a long work like the Book of Job, intentionally and successfully avoid all reference to historical occurrences, and to changes in religious forms or doctrines of a date posterior to that of the events which form the subject of his narrative (Spence-Jones, xv).
Harris ultimately pursues an early dating as well, and offers this interesting bit of information:
As to the historical background of Job, it seems to fit well with ideas and literature of the second millennium B.C. Pope remarks that “the ideas championed by Job’s friends were normative in Mesopotamian theology from the early second millennium B.C.” (p. XXXV) and he compares several works on suffering: From Egypt, the Dispute over Suicide and the Tale of the Eloquent Peasant, and from Mesopotamia, a lament called by S. N. Kramer The First Job. The Akkadian work I will Praise the Lord of Wisdom, also called The Babylonian Job, describes a sufferer who recovers, and the Dialogue About Human Misery, sometimes called the Babylonian Ecclesiastes is on a similar topic. Pope offers extracts from these works. They can be read conveniently in ANET. It should be noted that these works consider the problem of suffering, as does the book of Job, but their answer is quite different.
While Harris supports an older date, he lists a number of men who have held to later dating of exilic or post-exilic, including Pope, but also Pfeiffer, Driver, A. Bentzen, and Eissfeldt (who Harris notes had his late theory invalidated by the Dead Sea Scrolls find; Harris, 7-8). He also mentions "More scholars have now veered toward a pre-exilic date" (Harris, 8). It was already noted that a number do hold to a very early dating.
In the 19th century (and largely late into the 20th as well), Job was considered Wisdom Literature and that largely fostered the argument for Solomonic era dating (e.g. Lange et. al. states it "belongs to the group of Solomonic poems of Wisdom," 249). However, that association has recently been challenged, as Kaiser notes:
Until the last quarter of the twentieth century, Job was predominantly classified as Wisdom literature. But then a strong voice of opposition arose claiming that Job was either utterly unique or it was in a lament genre, a form that was not firmly established until recently (Kaiser, 131)8
Authorship is No Help in Dating
Spence-Jones notes that the only traditional view is that the author was Moses.
Aben Ezra (about A.D. 1150) declares this to be the general opinion of “the sages of blessed memory.” In the Talmud it is laid down as undoubted, “Moses wrote his own book” (i.e. the Pentateuch), “the section about Balaam, and Job” (Spence-Jones, xv)9
He does note as well theories (conjectures) of contemporary (to the events) authors (which would have authorship mainly in the Patriarchal period):
The most ingenious of the conjectures put forward is that of Dr. Mill and Professor Lee, who think that Job himself put the discourses into a written form, and that Moses, having become acquainted with this work while he was in Midian, determined to communicate it to his countrymen, as analogous to the trial of their faith in Egypt; and, in order to render it intelligible to them, added the opening and concluding sections, which, it is remarked, are altogether in the style of the Pentateuch. A far less probable theory assigns the authorship of the bulk of the book to Elihu (Spence-Jones, xvi).10
Since the author is ultimately unknown, that does not help much with dating, and one's decisions about dating or authorship influence the conclusions one draws for the other.
Harris believes dating of Ezekiel is fairly certain at roughly 600 BC, and the mention of Job in that book (14:14, 20) affirms the work being at least prior to that (Harris, 4). Indeed, the reference in Ezekiel assumes a familiarity with the person and his character, and thus assumes a general knowledge of the work.
Harris also mentions the similarity of Prov 3:11 and Job 5:17 (typo in the article has it as Job 5:27) as probably literary dependence (Harris, 4). He states:
The wording of the two passages is identical in Hebrew, except that Job has the divine name, Shaddai, which it very frequently uses, and Proverbs uses the more common name, the Tetragram [YHWH]. It also adds a characteristic proverbial touch, “my son.” The force of such a parallel is debatable, because it is hard to know which book quoted the other, granted that there was some verbal dependence.
Harris' final statement is odd, considering that it is commonly recognized that Shaddai is a far more ancient name (and in fact Harris himself notes that later; Harris, 6), and that Job's extensive use of it is one of the key earmarks of its antiquity. Thus, it is far more likely Proverbs is quoting Job if there is any literary dependence at all. In some further discussion of parallels to Psalms and Proverbs with Job, Harris does admit on the literary relations:
It does seem a little more probable that Proverbs and Psalms did the borrowing (Harris, 5).
One particular parallel to Psalms he makes is:
Job 71:17 [sic; should be corrected to Job 7:17] and Psalm 8:5. Job says, “What is man that you magnify him?” The Psalm says, “What is man that you remember him?” The word “man” in each case is the less used word for man, ʾenô̄sh, making literary interdependence more likely (Harris, 5).
Many other parallels to Scripture are discussed in Harris' work and should be consulted for more info on those. He does end that summary with this thought (emphasis added):
To sum up, there are a few interesting verbal parallels with Psalms, Proverbs, Isaiah, and the Balaam oracles. These are not conclusive, but incline somewhat toward a pre-monarchy date for the writing (Harris, 5).
And as noted earlier, Harris pushes the date to Mosaic or pre-Mosaic times.
Alden makes no commitment to a dating:
the door must be left open until some ancient text surfaces or some authentic reference to these people or this book comes to light (Alden, 27-28)
Smith makes a commitment, but hedges it:
The writing of the book is best assigned to the age of Solomon [ca. 950 B.C.], which was a time of literary flowering and interest in wisdom. There is nothing in the book, however, which conclusively refutes the ancient association of this book with Moses (Smith, ch.2)
Unger leans toward "Solomonic era" also (Unger, 379), and Cabal et al. say as well it is "perhaps a likely time" (Cabal, 734), a rather non-committal statement to qualify. Lange et al. also end up here (Lange, 248).
Spence-Jones held (from a view assuming an ancient composing of the Pentateuch as well):
It is a legitimate conclusion ... that the Book of Job is probably more ancient than any other composition in the Bible, excepting, perhaps, the Pentateuch, or portions of it. It must almost certainly have been written before the promulgation of the Law. ... On the whole, therefore, it seems most reasonable to place the composition towards the close of the patriarchal period, not very long before the Exodus (Spence-Jones, xv).
Harris concludes:
In the absence of definite evidences for late dating and in view of numerous indications of a patriarchal milieu, it seems possible to hold to a Mosaic or slightly pre-Mosaic date in accord with much old Jewish and Christian sentiment. However, the New Testament does not speak on either Job’s authorship or date, and the date is not of theological concern. We may therefore hold our conclusion provisionally expecting further light, especially from linguistic studies (Harris, 8-9)
My view of Scripture's formation easily holds to the possibility of a very early, patriarchal date. There appears to be little real evidence to refute that, and in fact much of the linguistic, style, genre, and other such literary evidences show relationships to 2nd millennium works, which simply reinforces the possibility of that.
But as I noted in the first heading, there is "no certain answer to give" on the date of its composition.
BIBLIOGRAPHY OF REFERENCED WORKS
Alden, Robert L. Job. Vol. 11, The New American Commentary. Nashville: Broadman & Holman Publishers, 1993. Logos Bible Software.
Archer, Gleason. Encyclopedia of Bible Difficulties. Grand Rapids, MI: Zondervan, 1982.
Cabal, Ted, Chad Owen Brand, E. Ray Clendenen, Paul Copan, J.P. Moreland, and Doug Powell. The Apologetics Study Bible: Real Questions, Straight Answers, Stronger Faith. Nashville, TN: Holman Bible Publishers, 2007.
Carson, D. A., R. T. France, J. A. Motyer, and G. J. Wenham, eds. New Bible Commentary: 21st Century Edition. 4th ed. Leicester, England; Downers Grove, IL: Inter-Varsity Press, 1994. Logos Bible Software.
Harris, R. Laird. "The Book of Job and Its Doctrine of God." Grace Journal 13 (1972):3-33.
Kaiser, Walter C., Jr. The Promise-Plan of God: a Biblical Theology of the Old and New Testaments. Grand Rapids, MI: Zondervan, 2008. Logos Bible Software.
Lange, John Peter, Philip Schaff, Tayler Lewis, Otto Zöckler, and L. J. Evans. A Commentary on the Holy Scriptures: Job. 1865–80. Bellingham, WA: Logos Bible Software, 2008. Logos Bible Software.
Smith, James E. The Wisdom Literature and Psalms. Old Testament Survey Series. Joplin, MO: College Press Pub. Co., 1996. Logos Bible Software. NOTE: no page numbers are given in the electronic version of this book, so references are to the chapter.
Spence-Jones, H. D. M., ed. Job. The Pulpit Commentary. London; New York: Funk & Wagnalls Company, 1909). Logos Bible Software.
Unger, Merrill F. Introductory Guide to the Old Testament. Grand Rapids, MI: Zondervan, 1951.
Zuck, Roy B. "Job" in John F.Walvoord, Roy B. Zuck, Dallas Theological Seminary. The Bible Knowledge Commentary: An Exposition of the Scriptures. Wheaton, IL: Victor Books, 1985. 1:714-777. Logos Bible Software.
NOTES
1 Similar notes about complexity of dating is found in Smith, ch. 2. Spence-Jones believes evidence "strongly favour the theory of its high antiquity" (xiv), but composition is at least after Job's death, based on Job 42:17 (xv). Unger says dating ranges from patriarchal times to as late as 3rd c. BC (378-379), while Cabal et. al. states, "All attempts to assign a date, whether on the basis of literary or linguistic data or with regard to its philosophical and theological viewpoint, have proved to be capable of variant interpretations and therefore inconclusive" (Cabal, 734). It should be noted that the work by Lange et. al. has an extensive listing of people who hold to various dating positions (Lange, §6, 243-249).
2 Similar to Alden, Smith states "events seem to have taken place ca. 2000 B.C. during the Patriarchal period," and gives five marks of antiquity (ch. 2). Zuck notes 9 marks (717). Spence-Jones states, "manners, customs, institutions, and general mode of life described in the book are such as belong especially to the times which are commonly called 'patriarchal'," and further dates Job (based on the approximate age he lived from Job 42:16) by his "term of life (two hundred to two hundred and fifty years) would seem to place him in the period between Eber and Abraham, or at any rate in that between Eber and Jacob, who lived only a hundred and forty-seven years, and after whom the term of human life seems to have rapidly shortened" (xv; similarly, see also Zuck, 717). Also affirming patriarchal: Unger, 378.
3 Smith, ch. 2., n.14 shows he is quoting "J. Sidlow Baxter, Explore the Book (Grand Rapids: Zondervan, 1966), 3:25."
4 One article online from 2011 that briefly notes this discovery about Aramaic is "Archaeological finds announced" from the Archaeology News Network (now found here; link updated 5/5/2023; originally accessed 7/30/2014 at a dead link; another source). The 2nd millennium BC corresponds in time frame to what is attested about Hebrew, which "developed during the latter half of the second millennium BCE between the Jordan River and the Mediterranean Sea, an area known as Canaan" (accessed 7/30/2014).
5 Archer notes a study by "A. Guillaume ('The Unity of the Book of Job,' Annual of Leeds University, Oriental Sec. 14 [1962-63]: 26-27) has convincingly argued that there are no demonstrable Aramaism in the speeches of Elihu (Job 32-37), which reputedly have the highest incidence of them. He contends that nearly all of them are terms existing in Arabic," and Archer comments this would be expected given the location of Uz "somewhere in North Arabia" (236).
6 Related to Alden's statement, see info on Ugaritic dating (accessed 7/30/2014). Also, Archer notes the antiquity of the name of Job as being 2nd millennium BC from other ancient documents (236).
7 Alden notes such concepts as Satan, resurrection and afterlife, and such. I personally believe that these are truths the ancients knew much more about than we today might think they did, and that the truth of these ideas was lost among the rise of paganism after the tower of Babel spread the people abroad. They become truths regained by the Israelites through God's revelation later in history.
8 Kaiser makes his statement based on the work he notes in n.1 of chapter 6, which is "Claus Westermann, The Structure of the Book of Job, trans. Charles A. Muenchow (Philadelphia: Fortress, 1981), p. 1, n. 1 and pp. 13–14."
9 Spence-Jones' two footnotes for those quotes are: (1) "‘Commentarius in Jobum,’ ii. 11" (his n.30), and (2) "‘Baba Bathra,’ p. 14, b. Compare Ephrem Syrus, ‘Jobi Librum Moyses scripsit.’" (his n.31). As Harris warns, this tradition is even quite late in attestation—5th c. AD at the earliest (Harris, 3-4).
10 Spence-Jones gives footnote information about Mill and Lee is "‘The Book of Job,’ Introduction, pp. 36–48." (his n.32-34). I personally believe that Elihu is the most likely original author, as he is the only person not rebuked by God in the book (perhaps indicating he is the most in-tune with God of all of them, even Job). Of course, I cannot prove that.
Establishing the date for the Book of Job is difficult, not least because it clearly had at least two authors over a period of some centuries. Part of the book is poetic and another, quite distinct part is prose. Some material appears to be post-exilic, but other parts reflect a much earlier belief system. This answer focuses on the Book of Job in the form it comes down to us today. Using several data of evidence from the book, we can establish a series of terminus post quem dates, the latest of which is most probable.
Job contains parallels to Deuteronomy, for example:
Job 2:7 (NIV): So Satan went out from the presence of the Lord and afflicted Job with painful sores from the soles of his feet to the crown of his head.
Deuteronomy 28:35: The Lord will afflict your knees and legs with painful boils that cannot be cured, spreading from the soles of your feet to the top of your head.
Timothy K. Beal says, in Religion and its Monsters, page 40, both books are talking about obedience and both books use the same Hebrew verb for inflict/smite: nakab. As Beal points out, the overall implication is that the author of Job knew the Book of Deuteronomy. Scholars generally agree that the Book of Deuteronomy originated as the 'book of law' supposedly found in the Temple during the seventh-century-BCE reign of King Josiah. A very similar case is reported in the Jeremiah chapter 36, where a document was hidden then 'found' by the priests, in order to disguise its authorship. Bernard S. Jackson says, in 'Ideas of law and legal administration: a semiotic approach', published in*The World of Ancient Israel: Sociological, Anthropological and Political Perspectives* (edited by R E Clements), page 193, this suggests that the scroll found in the time of Josiah, just a few years earlier, had also been a ‘plant’and that Jeremiah has given us a vivid description of how it might have been done.
The scholarly consensus of the age of the Book of Deuteronomy gives us the terminus post quem for the Book of Job, at least in its final form, as the seventh century BCE.
R. N. Whybray says in 'The social world of the wisdom writers', published in The World of Ancient Israel: Sociological, Anthropological and Political Perspectives, page 239, there is uncertainty about the date of the Book of Job, and even about the nationality of the author. A date in the Persian period (fifth or fourth century BCE) is at present the most favoured one, but such estimates are always made with hesitation. The chief reasons usually given for a post-exilic date are the speculative nature of the book's theology, especially compared with the older parts of the Book of Proverbs, and the acquaintance of the author with other Old Testament writings such as Isaiah 40-55 [written during the Exile].
Whybray says (ibid, page 240) the presence of the 'Satan' as a member of Yahweh's heavenly court is usually taken to be an indication that at least in its present form the story is post-exilic, since the only other references to that figure in the Old Testament (Zechariah 3.1 and 1 Chronicles 21.1) are certainly post-exilic.
From the evidence presented here, the Book of Job is post-exilic, probably written in the fifth or fourth century BCE.
It is worth noting that the order of books in the Bible has never been firmly established, and their order may vary from one Bible to another. The Jews organize the Old Testament scriptures into three sections, as noted in their acronym, "Tanakh." In Hebrew, this word has three consonants, the tav, the nun, and the kaf, which stand for the Torah, the Nevi'im, and the Ketuvim, respectively. The Torah is the law, particularly the Pentateuch, or five books of Moses; the Nevi'im are the prophets; and the Ketuvim, which are the other writings, include the books of poetry, of which Job is one.
Because Job is not a book of law, and is not an especially prophetic book, it is placed in the third section by the Jews, coming after the Torah and the Nevi'im. But, while this organization may well represent the relative importance of each book, it does not mean to say that the books are organized in their chronological order.
The evidence is strong for the book of Job actually being the very first book of the Bible written. As @ScottS indicated in the accepted answer here, there are indications from the linguistic style of the book, including "Aramaisms," that the book was very early.
It is certain that the people in the book of Job can be dated to the time prior to the forced servitude in Egypt. Let us examine that evidence.
Job himself was the son of Issachar, grandson of Jacob and Leah.
And the sons of Issachar; Tola, and Phuvah, and Job, and Shimron. (Genesis 46:13, KJV)
He lived in the land of Uz.
There was a man in the land of Uz, whose name was Job; and that man was perfect and upright, and one that feared God, and eschewed evil. (Job 1:1, KJV)
Uz was a son of Aram, grandson of Shem.
22The children of Shem; Elam, and Asshur, and Arphaxad, and Lud, and Aram. 23And the children of Aram; Uz, and Hul, and Gether, and Mash. (Genesis 10:22-23, KJV)
The Semites are the descendants of Shem, so Uz was a Semite just as Abraham was. These were part of the same family of God-worshipers. Shem himself lived to see Abraham's day, so it is likely that the family members, his descendants, were in contact and/or close to each other. Thus Job is said to live in the land of Uz, a relative of his.
Now when Job's three friends heard of all this evil that was come upon him, they came every one from his own place; Eliphaz the Temanite, and Bildad the Shuhite, and Zophar the Naamathite: for they had made an appointment together to come to mourn with him and to comfort him. (Job 2:11, KJV)
Only one of these three friends is mentioned outside the book of Job, so we will not consider the others.
And Adah bare to Esau Eliphaz; and Bashemath bare Reuel; (Genesis 36:4, KJV)
10These are the names of Esau's sons; Eliphaz the son of Adah the wife of Esau, Reuel the son of Bashemath the wife of Esau. 11And the sons of Eliphaz were Teman, Omar, Zepho, and Gatam, and Kenaz. (Genesis 36:10-11, KJV)
To be a "Temanite," Eliphaz would have had to be a descendant of Teman, not his father. So the Eliphaz named in Job was named after his predecessor, a son of Esau, Jacob's son, Abraham's grandson. Again, this is a relative of Job--one of the descendants of Shem.
Elihu was the son of Barachel, of the tribe of Buz.
And Elihu the son of Barachel the Buzite answered and said, I am young, and ye are very old; wherefore I was afraid, and durst not shew you mine opinion. (Job 32:6, KJV)
Buz was the son of Nahor, Abraham's older brother. (Note that Abram/Abraham was Terah's youngest son, despite being listed first on account of Abraham being in the Messianic line.)
20And it came to pass after these things, that it was told Abraham, saying, Behold, Milcah, she hath also born children unto thy brother Nahor; 21Huz his firstborn, and Buz his brother, and Kemuel the father of Aram, (Genesis 22:20-21, KJV)
So Elihu, son of Barachel, was at least the grandson or great-grandson of Buz, hence counted as a Buzite; and Buz, in turn, was the son of Nahor, Abraham's brother. This means that Job and Elihu would have been about third cousins once removed, or fourth cousins--not super close, but certainly family of the same era.
It almost goes without saying, but since the story took place after the scattering of the people at the Tower of Babel by the confusion of their languages, Job's and his friends' ability to speak with each other indicates they used a common language. Those speaking Hebrew and/or Aramaic at that time can be linked as descendants of Shem. (Aram was Shem's son, as noted earlier.)
Based on the genealogical record, Job would have been born shortly before his grandfather, Jacob, had entered Egypt during the great famine. He is counted among those who entered Egypt with Jacob. However, being said to live in the land of Uz, it is evident that he later moved back to the land of his relatives, outside of Egypt. After his trial, upon which the book of Job is written, he is said to have lived 140 years more.
After this lived Job an hundred and forty years, and saw his sons, and his sons' sons, even four generations. (Job 42:16, KJV)
Seeing as Job already had multiple adult children when the story began, we can estimate his age to have been in the neighborhood of at least fifty or sixty at that time, making his full life close to 200 years--"So Job died, being old and full of days" (Job 42:17, KJV).
Job's lifespan also helps date the story. After the time of Moses, such longevity as this is no longer recorded. Joseph and Joshua both died at 110 years old. Moses at 120. Living nearly 200 years was a thing of the past. But Abraham had lived to the age of 175 (see Genesis 25:7), and his son Isaac had lived to be 180 (see Genesis 35:28). Theirs was the era when nearly two-century lifespans were still being recorded. And this era shortly predated the time of Moses.
Moses lived during the time of forced servitude (slavery) in Egypt. Because, at the age of 40, he rashly killed an Egyptian to protect his Israelite comrade, and then learned it had not been kept secret, he was forced to flee Egypt, and he returned to the land of his distant relatives. For forty years he kept the sheep of his father-in-law, Jethro, also known as the priest of Midian (land of Midian). Midian was a son of Keturah, whom Abraham married after Sarah's death, so Midian was a descendant of Abraham, just as Job and Moses were.
Job was Moses' first cousin twice removed, as Job was the cousin of Moses' grandfather Kohath. That puts Job only two generations prior to Moses, and with Job being said to have seen four generations of his descendants, it is quite possible that Moses could have heard Job's story firsthand, from Job himself, during his time in the wilderness tending the sheep.
With nothing else on record to challenge his mental faculties during his time as a shepherd, and with many hours in the great outdoors during which to ponder the mysteries of life, this forty-year period of Moses' life aligns with the most ideal opportunity for the book of Job to have been written, with Moses as its author.
All the evidence points to the book of Job having been written by Moses during his 40 years as a shepherd, before he reached 80 years of age when he was called by God to lead the Israelites out of Egypt. This is the same time period in which Moses would have been writing the book of Genesis. This would date the books' writing to about 1500 BC. Whether Genesis was written first or Job was written first cannot be ascertained with any degree of confidence.
Septuagint:
In the Greek version of the Book of Job, at the end, there is the following addition: "This man (Job) is described in the Syriac book as living in the land of Ausis, on the borders of Idumæa and Arabia; and his name before was Jobab; and he, having taken an Arabian wife, begot a son whose name was Ennon. And he himself was the son of Zare, who was one of the sons of Esau, and Bosorrha; so that he was the fifth in descent from Abraham. And these were the kings who reigned in Edom, which country he also ruled over: first Balak, the son of Beor, and the name of his city was Dennaba; and after Balak Jobab."
