The Idea in Brief
Both the oral and written Jewish tradition (as codified in pre-Talmudic Midrashim and the Masoretic Text, respectively) indicate that the blindness, deafness, and muteness in this verse were that of the Egyptians, who would be unresponsive to the message of Moses to release the Jewish people from captivity.
Discussion
The first place to start in the Masoretic Text is the Masorah Parva, which are the marginalia (shorthand notes) on the leaves of the codex, which in turn reference the Masorah Magna (located at either the tops and bottoms of the page or at the end of the book and/or codex), which contains other scripture references or notes. The Biblia Hebraica Stuttgartensia has simplified this analysis for us. The key preposition-noun word in this verse, which the Masoretic editors draw to our attention, is לָאָדָם, which is for man. Please click here to see the translation of the Magna Parva and the corresponding reference at the foot of the page to the Masorah Magna regarding this phrase לָאָדָם.
First we note that this word אָדָם occurs 552 times in the Masoretic Text of the Hebrew Bible. The preposition-noun לאדם (that is, without any vowel markings) occurs 24 times in the Masoretic Text of the Hebrew Bible. However, the word-phrase לָאָדָם (that is, with the three consecutive Qameṣ vowels) occurs 12 times in the Masoretic Text of the Hebrew Bible. That is, the exact word occurs 5 times in addition to the 7 times in the Book of Qohelet. (The word occurs an eighth time there, and is the exception, because this word is spelled לְאָדָם in Ec 2:26, with the schwa under the lamed.) In other words, our software Bible tools confirmed what the Masoretes had written over 1,000 years ago, but without the aid of computers. Thus the Masorah Magna provides the same results found through the use of our Bible Software Tools. That is, according to Weil (2001) the notations are as follows, which as mentioned correspond to our double-checking with the aid of Bible software:
So when the Masoretic editors delimited the words and vowels by pointing us to the occurrences of the phrase לָאָדָם (with the three consecutive Qameṣ vowels in sequence), they are forcing us to look at what the five verses say in addition to the mentions in the Book of Qohelet.
Whether by coincidence or otherwise, these verses refer to the disobedience of man, whose heart does not obey the Creator. Thus the Masoretic editors indicate to the reader that Jewish tradition had understood the dumbness, deafness, and muteness to refer to the hardened heart of man, and not to non-functioning physiological parts of the body (ears, ears, voice). In other words, the Masoretic editors want us to see the dumbness, deafness, and muteness as moral and spiritual. Further evidence from the text reinforces this hypothesis.
In his research, Bailey (2010) identified two chiasms in the immediate text at hand, which he translated in parallel as follows:
And Moses said unto Yahweh, “O Lord,
A I am not a man of words,
B Neither yesterday, Nor the day before
B′ Since you spoke to your servant
A′ Because I have a heavy mouth and heavy tongue.”
A Who placed [words in] man’s mouth?
B Or who makes him mute or deaf?
B′ Or seeing or blind?
A′ Is it not I, Yahweh? I am/will be with your mouth to teach you what to say.
In other words, Moses said that no one has listened to him before, and no one will listen to him at the current time, and therefore the Lord has to find someone else to save the Israelites. The Lord makes the parallel reply via chiasm and states that the muteness and deafness are to be parallel to people who do not listen (chiasm B = chiasm B'). That is, people who do not see are people who do not understand, because the Lord has not illuminated them to the truth. These two chiasms are important because they point to the deafness, muteness, and blindness as spiritual in contrast to the non-responsiveness given to Moses, and therefore physical handicaps are NOT in view. (In this regard, the Lord was relating to Moses a few verses later in the same chapter in Ex 4:21 that he would harden the heart of the Pharaoh.) Finally, Jewish oral tradition provides MORE evidence as captured in the Midrash writings of rabbis written during the Tannaitic and Amoraic periods of early Rabbinic Judaism (approximately 70–500 of the current era). That is, the deafness, muteness, and blindness created by the Lord are not physical, but moral and spiritual handicaps.
According to Nelson (2006), in the Halakhic Midrash, Tractate Sanya, the following occurs in Chapter 2, Section V -
C. Moses responded before the Holy One, blessed be He, “Master of all the world! You have said to me, ‘Go down to Egypt and bring the children of Israel out of Egypt!’ But I am afraid of the people from whom I fled!”
D. He [i.e., God] said, “Don’t be afraid of them, for all of them have died! As it says in Scripture, ‘...for all the men who sought (to kill you) are dead’ (Exod. 4:19).”
7 E. The Holy One, blessed be He, responded [further] to Moses, “Who rendered the men Pharaoh sent to catch you mute, deaf, and blind? Was it not I? As it says in Scripture, ‘Who gives man speech? (Who makes him dumb or deaf, seeing or blind? Is it not I, the Lord?)’ (Exod. 4:11).”
(Textual Source: JTS Rab. 2404, folios 1–2 and Notes of Rav Abraham Ha-Laḥmi—רב הגהות אברהם הלחמי)
The blindness, deafness, and muteness in this passage was understood in oral Jewish tradition to be moral and spiritual. In addition, Rabbi Shlomo Yitzchaki also mentions yet another citation from the Aggadic Midrash, and he cites as follows:
[O]r who makes [one] dumb: Who made Pharaoh dumb, that he did not exert any effort [to issue his] command to kill you? And [who made] his servants deaf, so that they did not hear his commandment concerning you? And who made the executioners blind, that they did not see when you fled from the [executioner’s] platform and escaped?-[from Tanchuma, Shemoth 10]
In summary, during (or perhaps before) the period of the creation of the Talmud and codification of the Masoretic Text, this Mishnah texts cited above indicated that the blindness, deafness, and muteness found in Exodus 4:11 were in reference to the Egyptians, and therefore were moral and spiritual.
Conclusion
The written Masoretic Text; the context (or chiasmic order of discussion between Moses and the Lord); and the oral tradition as found in rabbinic Midrashim indicate that the deafness, blindness, and muteness found in Exodus 4:11 were not related to physical handicaps, but moral and spiritual handicaps. As is evident in the same (con)text in Exodus 4:21, the Lord's intent was to harden the heart of Pharaoh, who would not see, hear, nor see (understand). That is, it was not until the same Egyptians were crossing the Red Sea behind the Israelites with great difficulty that they had realized that "the Lord was fighting for Israel" (Exodus 14:25). It was at that point that their eyes were opened and they tried to turn back to save their lives, but it was too late because the water then rushed down and drowned them all at that very moment.
REFERENCES:
Bailey, R. C. (2007). Exodus. Joplin, MO: College Press Publishing Company, 91.
Nelson, W. D. (2006). Mekhilta de-Rabbi Shimon bar Yohai. Philadelphia: Jewish Publication Society, 9.
Weil, G. E. (2001). Massorah Gedolah: Manuscrit B. 19a de Leningrad. Rome: Pontificium Institutum Biblicum, 47.