In Gen. 2:24, it is written,
24 Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh. KJV, 1769
כד עַל־כֵּן֙ יַֽעֲזָב־אִ֔ישׁ אֶת־אָבִ֖יו וְאֶת־אִמֹּ֑ו וְדָבַ֣ק בְּאִשְׁתֹּ֔ו וְהָי֖וּ לְבָשָׂ֥ר אֶחָֽד׃ WLC
How exactly do a husband and wife “become one flesh”?
This verse cannot be taken in isolation from those immediately around it. So let me quote Gen 2:20b-25 (KJV; slightly reformatted and some Hebrew words noted):
but for Adam there was not found an help meet for him. 21 And the LORD God caused a deep sleep to fall upon Adam, and he slept: and he took one of his ribs, and closed up the flesh [בָּשָׂר] instead thereof; 22 And the rib, which the LORD God had taken from man, made he a woman, and brought her unto the man. 23 And Adam said,
This [זֹאת] is now [פַּ֫עַם] bone of my bones, and flesh [בָּשָׂר] of my flesh [בָּשָׂר]: she shall be called Woman, because she was taken out of Man.
24 Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh [בָּשָׂר].
25 And they were both naked, the man and his wife, and were not ashamed.
First, the previous three uses of the masculine noun בָּשָׂר (bāśār, "flesh") are quite clear to be referring to the physical skin/meaty part of the human body, contrasting explicitly with the bone in v.23. This meaning then should be expected for the term in v.24 because of the use in the immediate context.
Second, Adam's statement is key to the meaning. He refers to this (זֹאת; feminine form of זֶה, "this [one]") female of his own kind (contrasted with the v.19-20 creatures) as now (פַּ֫עַם) bone of his bone and flesh of his flesh. The term פַּ֫עַם often has the idea of an occurrence of something, and thus the word used when speaking of repetitive occurrences, or X number of "times" of something, including a "once" time idea (e.g., Gen 18:32, Jud 16:28).1 Hence why the translation of "now" with respect to timing, but the word has the definite article on it in the text (הַפַּ֗עַם). The paring of the article with this word indicating time makes it most likely demonstrative,2 and v.23a can be rephrased like so:
This [female of my kind] is this [one] time bone of my bone and flesh of my flesh3
What is Adam making this statement in reference to? It was in response to God having "brought her unto" him (v.22). Thus, while Eve was indeed literally taken from Adam's side (v.21), and so literally came from his flesh and bones, it is at the presentation of her to him by God as the companion "meet for him" (v.20b), or "comparable to him" (NKJV), that Adam acknowledges as the timing of when "this once" she (as an individual herself) is considered bone and flesh of his. So Adam is utilizing the literal facts of her creation as a foundation for making a figurative reference about their relationship now as two individuals, doing so as an acknowledgment of the unity of the companionship he was to have with her. They would function together as companions, but together as if they were one flesh, one being.
Third, v.24 is then an affirmation made that this uniting of a man and a woman in companionship together was to function the same for all generations of mankind, the two were to be as if they were one flesh, one being.
It is interesting that from the context it is difficult to determine for sure if v.24 is intended to convey:
Whatever the basis for the statement, Adam's reflection is used as the basis for the institution of marital companionship, the leaving of the ones who beget (the father and mother), and the uniting of the two that are intended to function as one on earth. The unity was in part to beget more people themselves (Gen 1:27-28a) and in part to achieve the dominion granted mankind over the earth and its creatures (Gen 1:26, 28b; one person could not properly oversee all the earth and its creatures alone), both of which are why the creatures of v.19-20 were unsuitable.
This is likely the intent of Moses for the phrasing of v.24, and God's point through Moses (and possibly Adam's point, if it is a continuation of his speech). So how they become one flesh is by their union as companions meet for each other, a union that happens once as the man moves from the parent's familial authority to become his own family authority in union with that one woman who joins him at that time to do that with—i.e., marriage, including the physical (sexual) union intended to go with that. God's approval is on that union, whatever the cultural accouterments, assuming such a union is in fact a commitment of such companionship, and not merely a liaison of the flesh.4
This perfect unity that Adam declared and God intended is, I believe, the chief basis for why Adam chose to eat the forbidden fruit after Eve (his companion) had been deceived and had already ate of it (Gen 3:1-6). Eve's action placed Adam in a straight betwixt
In short, Eve's being deceived was the serpent's clever way of placing Adam in a position of choosing between two "rights" (obeying God's command and being what God intended Adam to be in relation to unity with his wife), yet both "right" decisions appeared to have consequences that were "wrong" for what God had intended.
Adam chose to act in his flesh (as one flesh) and to stay united in nature with the one God gave Him over not transgressing the law God had given. This act of Adam's, while certainly reaping more consequences than he fully comprehended, is nevertheless probably the ultimate picture of acting as one flesh for the purpose of unity with one's companion that God joined one to* throughout history (there is no other purpose as to why Adam chose to eat in the context than this context of unity immediately preceding the temptation). Unfortunately, the keeping of the unity by this act is what caused disunity between Adam and Eve (Gen 3:12, 16) and them with God (Gen 3:8, 10).
NOTES
1 Ludwig Koehler, Walter Baumgartner, M. E. J. Richardson, and Johann Jakob Stamm in The Hebrew and Aramaic Lexicon of the Old Testament (Leiden; New York: E.J. Brill, 1999) state under the word that the "118 instances [the term is found], of which 100 have the meaning time."
2 Ronald J. Williams in Williams' Hebrew Syntax (Toronto: University of Toronto Press, 2010) notes numerous uses of the article, but the demonstrative use is the most likely here, and Williams' also notes Gen 2:23 as such a use (page 37, sec. 87).
3 Examples of the "this once" (i.e. this one time) idea via an articular הַפַּ֗עַם) פַּ֫עַם) when no other numerical value is given are easily found in the Hebrew text of Scripture. As noted, in Genesis 18:32 Abraham promises to just "this once" more ask YHWH about His saving Sodom and then in Judges 16:28, Samson prays "this once" for God to give him strength back to have vengeance on the Philistines. Gideon makes a similar "this once" more final prayer call to YHWH regarding the fleece in Jdg 6:39. The idea refers to the uniqueness of the event, that "this once" is being indicated as some final form at present (e.g. Gen 29:34-35 with Leah's speeches), as it is this instance of whatever event is being referred to. Hence why many English translations use "now" (KJV, NKJV, NASB, NIV), for that word conveys a reference to the time and event that just transpired. The other most common translation is "this at last" (ESV, NLT, HCSB, ISV, NET), emphasizing the "finality" of it at that moment. Both ideas refer to the event in question.
So my choice of "this [one] time" is simply an expanded idea of "this time" (i.e. "now") or "this once," to help an English reader see that it is the "time" aspect in reference to a particular event (the bringing of God to Eve) that is critical. "Now" or "this at last" convey the same idea, the point is that the idea of instances of an event is what the word is used for, and when articular and singular, refers to the unique events at that moment.
4 If one holds to the New Testament revelation on this (I do), then 1 Cor 6:16 clearly indicates the sexual union is the physical outworking of this unity of companionship. Sexual union is a physical picture expressing the unity of the two people as one flesh/body, and when sex involves a harlot, it pictures unity with the wrong person, where no real unity exists, while also fracturing the picture intended of unity with the wife.
5 It is not clear that Eve would have died if Adam had not chosen to eat. The command was explicitly given to Adam (Gen 2:16-17) prior to Eve's creation (Gen 2:18-25), so the command was explicitly to the first human individual, the male, Adam. (For New Testament commentary on this, see 1 Tim 2:13-14 and Rom 5:12, which attributes all people's death to Adam's transgression—which by extension would include Eve's death was because of her unity with her partner who transgressed.) Perhaps because of their unity or perhaps because Adam or God told her so directly [which if so is only revealed by her here, not elsewhere in the context], Eve certainly had taken the command to be for herself as well (Gen 3:2-3).
Comparing several translations, there is a wide variety on how the verb וְדָבַ֣ק is translated. The NIV uses "is united", ESV "hold fast", NASB "be joined", NRSV "clings", while older translations (KJV, ASV, Douay-Rheims) use "shall cleave". Cleave is an archaic word that is not really used much anymore, but its seems every modern translation uses something different, so let's look at the original Hebrew.
The root of וְדָבַ֣ק is דָּבַק (dabaq). The verb occurs 54 times in the Old Testament. It can have a literal meaning of cling/stick to, for example Job 19:20:
My bones stick (דָּבְקָ֣ה) to my skin and to my flesh, and I have escaped by the skin of my teeth. (ESV)
It can also be used figuratively, as is presumably the case on Genesis 2:24. BDB suggests passages that likely use dabaq is the same sense as our passage:
And his soul was drawn (וַתִּדְבַּ֣ק) to Dinah the daughter of Jacob. He loved the young woman and spoke tenderly to her. (Genesis 34:3, ESV)
from the nations concerning which the LORD had said to the people of Israel, “You shall not enter into marriage with them, neither shall they with you, for surely they will turn away your heart after their gods.” Solomon clung (דָּבַ֥ק) to these in love. (1 Kings 11:2)
For if you turn back and cling (וּדְבַקְתֶּם֙) to the remnant of these nations remaining among you and make marriages with them, so that you associate with them and they with you, (Joshua 23:12)
Then they lifted up their voices and wept again. And Orpah kissed her mother-in-law, but Ruth clung (דָּ֥בְקָה) to her. (Ruth 1:14)
and so on. The common theme here seems to a deep emotional attachment. Two of the passages specifically mention marriage, and the Genesis 34 passage eventually leads to marriage as well.
That said, dabaq can also be used for "overcome" and "keep", but what one does not find in any of the 54 Biblical uses is a sexual connotation.
To back up BDB's classification of Genesis 2:24 as emotional attachment instance, we can see how ancient translators, who were much closer to the original language than we are, took the word. The Septuagint has προσκολληθήσεται, which has a literal sense of "stick to", but when used in regards to human relationships means something like "be faithfully devoted to", especially when used to describe husband-wife relations. (BDAG)
Targums Onkelos and Neofiti have וְיִדבֹק which has more or less the same range of usage as dabaq. Pseudo Johnathan, however, uses מִבַעֲלַה which can mean "be associated with" or "make a partner of".
Finally, the Peshitta has ܘܢܩܼܦ which can mean "adhere to", "join to", or even "be betrothed to".
As such, the ancient translations support understanding וְדָבַ֣ק as joining together in a close relationship. The NET translation notes agree with my analysis, writing:
The perfect with vav (ו) consecutive carries the same habitual or characteristic nuance as the preceding imperfect. The verb is traditionally translated “cleaves [to]”; it has the basic idea of “stick with/to” (e.g., it is used of Ruth resolutely staying with her mother-in-law in Ruth 1:14). In this passage it describes the inseparable relationship between the man and the woman in marriage as God intended it.
(They explicitly connect the passage to marriage, which I have not yet done, but I felt the quote fit best here rather than later.)
Genesis 2:24 states that the man and women shall be/become one flesh (לְבָשָׂ֥ר). The root word בָּשָׂר (basar) is used quite often in the Old Testament (270 times). It is usually translated as flesh, but occasionally body.
The key to understanding the word here is to notice that it is also used in Genesis 2:21 and 2:23:
So the LORD God caused a deep sleep to fall upon the man, and while he slept took one of his ribs and closed up its place with flesh (בָּשָׂ֖ר). And the rib that the LORD God had taken from the man he made into a woman and brought her to the man. Then the man said, “This at last is bone of my bones and flesh (וּבָשָׂ֖ר) of my flesh (מִבְּשָׂרִ֑י); she shall be called Woman, because she was taken out of Man.” (Gen 2:21-23, ESV)
The author of Genesis is making an analogy. The flesh (literally a rib) that was taken from Adam to create Eve is metaphorically "returned" to create a whole. Adam is missing apart of himself. He is literally and metaphorically incomplete without Eve. Likewise, a man is incomplete without a woman. The author is saying that man needs to be united with woman.
This connection, while obvious enough from the repeated use of basar, is made explicit in the text. The Hebrew phrase עַל־ כֵּן֙, translated by the KJV as "therefore", draws a connection between what precedes and what follows. The previous verse(s) provide the reason why a man leaves his parents, seeks out a woman, and unites with her to become one flesh. Furthermore, it sets up Genesis 2:24 as a comment on the preceding verse by the narrator; that is, distinguishes it from Adam's speech. (Compare Genesis 10:9; 26:33; 32:32.) As such, the NET translates the phrase "That is why".
The word "flesh" carries a slight sexual connotation in English. However, there is no evidence that the author was thinking of a sexual union in Genesis 2:24. As already discussed, the verb dabaq does not support a sexual union. The noun basar also does not support a sexual connotation. Of 270 uses in the Old Testament, I believe the word is used in connection with sex in Ezekiel 16:26 ("You also played the whore with the Egyptians, your lustful [literally "of great flesh"] neighbors, multiplying your whoring, to provoke me to anger." (ESV). By far the normal meaning is literal flesh or as a metaphor for the whole body. If either of those meanings makes sense in context (which they do), it would be irresponsible to postulate an obscure metaphor for sex. None of this, of course, means that sexuality is excluded from the union, only that it it is not the defining trait.
What then is the nature of the union? According to most commentators, Genesis 2:24 is setting up the base for marriage. Targum Onkelos agrees. In v23 we find "And Adam said, This now is bone of my bone, and flesh of my flesh: this shall be called Woman, because from her husband (מִבַעֲלַה) this was taken." The word מִבַעֲלַה means "husband" or "master", but not simply "man". It seems the Targum's author clearly has marriage in mind.
This interpretation is also backed by Malachi:
But you say, “Why does he not?” Because the LORD was witness between you and the wife of your youth, to whom you have been faithless, though she is your companion and your wife by covenant. Did he not make them one, with a portion of the Spirit in their union? (Malachi 2:14-15a, ESV)
Here, the author makes a clear allusion to Genesis 2:24 and ties it to the marital union. He continues:
“And what was the one God seeking? Godly offspring. So guard yourselves in your spirit, and let none of you be faithless to the wife of your youth. For the man who does not love his wife but divorces her, says the LORD, the God of Israel, covers his garment with violence, says the LORD of hosts. So guard yourselves in your spirit, and do not be faithless.” (2:15b-16)
Malachi thus argues that because the martial union has created one flesh, to divorce is an act of violence, a ripping apart of flesh so to speak.
Genesis 2:24 is about marriage. The grammar does not support reading the passage as simply a sexual union and the flow of the analogy from Genesis 2:21-2:24 suggests that a man is incomplete without a wife. This is how ancient translators and interpreters saw the passage. The conclusion is also reinforced by Genesis 2:18 which says that God wanted to create a partner for Adam because he was alone. He needed companionship, and to fill this need a being of like substance was created out of his own flesh. Man's need for companionship is not fulfilled via sex, nor does a sexual union make him complete. Only a deep relationship, united in marriage, can do that. The traditional interpretation that the passage is providing the basis for the marital union is correct.
Based on my analysis I endorse the NET translation of 2:24 as a significant improvement over most translations:
That is why a man leaves his father and mother and unites with his wife, and they become a new family.
According to Genesis 2:24, a man and a woman become "one flesh" via the act of marriage. The passage does not explicitly state how marriage is defined, but it is clear that something more than a sexual union is in mind. Instead, the author's intention is to provide a reason why marriage occurs, and his answer is that man is incomplete without woman. Marriage unites husband and wife to form "one flesh", a complete being.
Marriage is the 1st Covenant that God gave man, and it existed before the Fall.
Keil and Delitzsch Commentary states:
They are the words of Moses, written to bring out the truth embodied in the fact recorded as a divinely appointed result, to exhibit marriage as the deepest corporeal and spiritual unity of man and woman, and to hold up monogamy before the eyes of the people of Israel as the form of marriage ordained by God. But as the words of Moses, they are the utterance of divine revelation; and Christ could quote them, therefore, as the word of God (Matthew 19:5)
God created Eve to be a "help meet"(עֵ֖זֶר כְּנֶגְדֹּֽו׃ -"suitable helper), (Gen. 2:18)
And the LORD God said, It is not good that the man should be alone; I will make him an help meet for him.
This goes beyond creating a female, God brought Adam a "wife" which constitutes a union in which offspring would result. Since a man leaves his father and mother, and "joins" himself freely and without volition(same being true for the woman) they are looked upon by God as "One Flesh"(לְבָשָׂ֥ר אֶחָֽד׃). They may expose their nakedness to each other because God has joined them together as Husband and Wife, under His Blessing. Consequently, the fruit of their union is "One Flesh", as the seed and the ova are inextricably joined to form a child.
Jesus's statement in Matt. 19:5-8 confirms what Moses intended when he wrote Gen. 2:24,
And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh? 6Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder. 7They say unto him, Why did Moses then command to give a writing of divorcement, and to put her away? 8He saith unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so.
Moses allowed divorce in the Law; but understood God's intention from the beginning as "One Flesh", of which death was the only reason for separation. God's Covenant "joining" of the Husband and wife made them "One Flesh", and no man was intended to alter His Covenant.
The sexual bond has the normal result in the birth of the child, who is "one flesh" with his parents in the literal sense. Under typical and normal life circumstances, the parents will provide for the essential and personal needs of the child such as love and intimacy.
This "one flesh" bond with the parents however ends when the child grows and bonds sexually with another person who, in turn, replaces the parents for continuing to provide essential and personal life needs such as love and intimacy. Under typical and normal life circumstances, this sexual pair-bond relationship will result in children, and so the cycle continues.
Thus the "one flesh" is literal (child) and/or sexual (parents), which results in providing essential personal life needs such as love and intimacy. Any brokenness in this regard will skew the life of the child and/or adult. For example, the "one flesh" principle appears in the Fourth Commandment, which is "Honor your father and mother so that your days may be prolonged in the land." The implication here is that brokenness occurring from the "one flesh" relationship with parents may correspond to ones brokenness in "one flesh" marital relationship as an adult.
The Masoretic Text is brief and ambiguous, however the Samaritan Pentateuch, the LXX, the Peshitta, and the Western Targum Pseudo-Jonathan (which all pre-date the Masoretic Text) provide clarification regarding the "one flesh" concept.
Gen 2:24 (WLC)
The Masoretic text does not clarify who are the "they" (highlighted in red color). In other words, does the "they" include the mother and father becoming one flesh with their son and his wife? According to the Critical Apparatus of the Biblia Hebraica Stuttgartensia the following comment appears for the Hebrew word words וְהָי֖וּ, which is the word highlighted in red (above).
The "translation" of this comment would be as follows: The Septuagint (in addition to the Peshitta, Targum Jonathan, and Latin Vulgate which offer similar readings albeit not literal) adds “the two” which corresponds to the Hebrew word שְׁנֵיהֶם for “the two,” which appears in the Samaritan Pentateuch.
While the Samaritan Pentateuch indicates that the man will be "one flesh" independent apart from both (משניהם) his father and mother (which is also correct), the other pre-Masoretic witnesses indicate that the "man" in Gen 2:24 refers not only to the male offspring of the father and mother, but the female offspring as well. The male and female offspring of mothers and fathers will unite in pairs to become "one flesh." The emphasis here is on the separation from the father and mother, and the sexual pair bonding of one male and female (congruent with parents as one male and one female) to become "one flesh."
First, the child is "one flesh" in the literal sense with his parents, which includes dependence upon the parents for essential life needs. When the child matures and unites with one member of the opposite sex, the "one flesh" relationship moves from parents to partner. That is, the parents no longer provide essential and personal life needs; instead the marital partner becomes the source of those needs.
Second, any desecration within the "one flesh" pair bond (between parents and children and/or between married couples) will have adverse consequences. For example, adultery destroys trust in another to provide ones essential life needs for intimacy, love, respect, and so forth. Brokenness too between the "one flesh" of parents and children may carry forth into the "one flesh" relationships of those same children in adulthood, which may even drive tendencies toward adultery as adults. In this respect, the quality of the marital "one flesh" relationship will have roots (for better or worse) in the previous "one flesh" relationship of the man and woman with regard to their respective relationships with their own parents.
Finally, indiscriminate or promiscuous behavior (by someone single, for example) is to sexually bond with multiple persons in the expectation of meeting essential and personal needs for pleasure, intimacy, and love. This multiple pair bonding interferes with the original divine intent of bonding with just one person, and therefore previous "one flesh" relationships will carry into future "one flesh" relationships; that is, like children with brokenness with parents, the baggage, brokenness and even shame cascade forward into the "one flesh" relationship with ones eventual marital partner. In this particular respect, sexual immorality is the committing of sins against "ones own flesh" (1 Cor 6:18).
(# 1): Husband and wife: God wanted man and woman to be fertile, becoming one during reproduction, and bringing children with chances at heaven. However, God wanted only a married couple reproducing. The commandment against adultery would say that, as would some other Scripture. E.G….
1 Corinthians 6:15-16 (KJV) 15 Know ye not that your bodies are the members of Christ? shall I then take the members of Christ, and make them the members of an harlot? God forbid. 16 What? know ye not that he which is joined to an harlot is one body? for two, saith he, shall be one flesh.
One key reason for the flood was all of the adultery and evil God saw at the time. Gen 6:1-13, with Noah being the exception.
Genesis 6:8-9 (KJV) 8 But Noah found grace in the eyes of the LORD. 9 These are the generations of Noah: Noah was a just man and perfect in his generations, and Noah walked with God.
Right after the flood, since God wanted Noah to remain just, He spoke to Noah and the only three men who would people the earth (i.e. his sons Shem, Ham, and Japheth).
Genesis 9:7-9 (KJV) 7 And you, be ye fruitful, and multiply; bring forth abundantly in the earth, and multiply therein. 8 And God spake unto Noah, and to his sons with him, saying, 9 And I, behold, I establish my covenant with you, and with your seed after you;
(# 2): Godly seed/offspring: By becoming one flesh for proper reproduction, the husband and wife would be the couple bringing the next flesh (i.e. children). He reminded marriage brought their covenant. E.G.
Malachi 2:14-15 (KJV) 14 Yet ye say, Wherefore? Because the LORD hath been witness between thee and the wife of thy youth, against whom thou hast dealt treacherously: yet is she thy companion, and the wife of thy covenant. 15 And did not he make one? Yet had he the residue of the spirit. And wherefore one? That he might seek a godly seed. Therefore take heed to your spirit, and let none deal treacherously against the wife of his youth.
NOT A LITERAL EXPRESSION:
Moses doesn't explain what he means by the expression: "shall become one flesh" (Gen 2:24), but that it should not be understood literally, is evident from the context. The husband and wife clearly remain distinct and separate individuals, though the one is said to "cleave to" the other in the marital union, which changes the way they regard each other thereafter.
A NEW RELATIONSHIP:
Though still distinct individuals, they are to regard themselves as "one flesh" in the sense that their two separate bodies, joined in marriage are to be viewed as a new entity, now functioning as one. This new relationship supersedes all previous relationships (Gen 2:24).
MUTUALLY DEPENDANT:
So, just as the body has many distinct parts that all function together as one unit, so the two marriage partners, are now to function as “one flesh”. The are no longer to regard each other as independent but as mutually dependant. As the apostle Paul explains: “The wife does not have authority over her own body but yields it to her husband. In the same way, the husband does not have authority over his own body but yields it to his wife” (1 Corinthians 7:4 NIV).
A PROFOUND MYSTERY:
This involves an act of voluntary submission each to the other (21-23) out of genuine love and mutual respect and mirrors the relationship of Christ to his body, the church.
When a man's organ called a penis enters into the woman organ called a vagina. The two bodies literally become one flesh.
"Or do you not know that anyone who is united with a prostitute is one body with her? For it is said, "The two will become one flesh." (1 Corinthians 6:16 NET Bible)
Simple logic may stand as the second witness. What real promises or ceremony gets involved with the joining of a prostitute? Now if a man joining with a prostitute gets directed to the statement "The two will become one flesh." This simplifies the concept of "The two will become one flesh." to a very simple explanation.
For it was only the exchange of money that causes "The two will become one flesh." Then indeed no one should ever use money. Therefore the only other act involved with prostitution "the action".
Really where was the officiator for Adam and Eve's marriage? Where where their wedding vows? Or are you telling me that they where never married in the sight of the Lord. Do you mean to tell me that Adam and Eve had premarital sex?!? Now why did the death penalty not come for this instead of the knowledge of function and error?
Genesis frequently uses a pattern or theme of return to the initial state. For example, Genesis 3:19 states,
By the sweat of your brow you will eat food until you return to the ground, for out of it you were taken; for you are dust, and to dust you will return.”
In the story of Noah, God returns to the beginning state of creation (the waters) by flooding the earth and the rest of The Bible is centered on returning man to the state before the fall vis-a-vis the sacrifice of Jesus, so this is both a Macro theme and a Micro theme.
The statement than man and woman will be one flesh appears to be another example of that theme of returning to the initial state. It is not that Adam and Eve are becoming one flesh, but that they are becoming one flesh again.
This interpretation is largely dependent on the specifics of the creation of Eve. Many scholars believe that Adam was initially crated as possessing both male and female aspects. This is not the same as androgynous, but instead Adam was dual-gendered, both fully male and female until the creation of Eve. According to this school of thought, the word "rib" would be better translated as "side" or "side chamber" and when God created Eve he took a part of the man's side chamber with which to create eve. In other words, god literally took a part of Adam - the female part - and used it to create Eve.
If this is the case, then Adam and Eve are becoming one flesh again through marriage and without Eve, Adam is literally missing a peice of his soul. By becoming one flesh Adam and Eve return to the initial state of creation - the way God meant for man to be, yet mankind is no longer alone. Through marriage that peice of Adam that was taken from him is returned to him and Adam and Eve are again "one flesh".
