Verse 10: And Moses said unto the LORD, O my Lord, I am not eloquent (Heb. a man of words), neither heretofore (Heb. since yesterday, nor since the third day), nor since thou hast spoken unto thy servant: but (Ex. 6:12; Jer. 1:6) I am slow of speech, and of a slow tongue.
[I beseech] Or, I beg: that is to say, Spare me, do not send me (Menochius, Lapide). It is an adverb of entreaty (Rivet).
[בִּי] O Lord: verbatim, for my sake (Rivet), or, in my case, or, my Lord (Oleaster). See on Genesis 43:20.
[Not eloquent] Hebrew: not a man of words: Symmachus: οὐκ εὔλαλος, that is, not able to speak fluently (Drusius, thus Vatablus, Fagius). It is proper that those that are about to speak to princes be of such a sort (Fagius, Vatablus). Not suitable (Septuagint). I do not have good pronunciation (Arabic). Hence Moses was βραδύγλωσσον, that is, slow of speech, says Lucian in Philopatris. There was chaos and night…and God removed this confusion by his word alone, ὡς ὁ βραδύγλωσσον ἐπεγράψατο, as the one slow of speech wrote (as Moses wrote) (Gataker).
[From yesterday and the day before yesterday, etc.] That is, Hitherto. The Greeks use χθὲς καὶ πρώην, yesterday and the day before yesterday, only of a recent even (Grotius). It is a Hebraism, that is, I have never been eloquent (Fagius, Vatablus, Menochius). What follows teaches that this is the sense (Vatablus).
[Even from the time that thou didst speak, etc.] That is, By thine address I have not become more eloquent (Rivet). Although thou art wont to render men more eloquent, and to provide them with the things necessary for those things unto which thou sendest them (Bonfrerius). Others thus explain it: The tongue is more hindered to me after thou didst speak with me, for man is rendered weaker on account of the presence of the Divine majesty, as it is said in Daniel 5:6. Others thus: from the time that thou didst speak, etc.; even thou thyself hast been able to understand that I am not eloquent (Estius).
[Of a more hindered and slower tongue] Hebrew: heavy with respect to mouth, etc.; that is, I am slow of speech, and of a hindered tongue, so that they would not be able to understand me when I speak. Thus Ezekiel 3:5, 6. Those that they were not understanding are called a people of a heavy tongue (Fagius, Vatablus). God willed to call Moses, hindered with respect to his tongue, to great works, so that the praise might be rendered to God, and not to the eloquence of Moses; so that the accomplisher of the signs by these defects, which he was not able to emend, might be kept in humility (Menochius).
I am not eloquent; not able to deliver thy message acceptably and decently, either to Pharaoh or to the Israelites. Since thy appearance to me, thou hast made some change in my hand, but none in my tongue, but still I am, as I was, most unfit for so high an employment. But indeed he was therefore fit for it, as the unlearned apostles were for the preaching of the gospel, that the honour of their glorious works might be entirely given to God, and not to the instruments which he used.
Verse 11: And the LORD said unto him, (Ps. 94:9) Who hath made man’s mouth? or who maketh the dumb, or deaf, or the seeing, or the blind? have not I the LORD?
[Who made?] Hebrew: Who placed? that is, gave? To place is frequently in the place of to give among the Hebrews (Vatablus).
[The seeing (thus nearly all interpreters), פִקֵּחַ] The one that is strong with respect to the senses (Junius and Tremellius); strong with respect to hearing and seeing (Piscator). For פִקֵּחַ is used concerning him who opens either eyes or ears (Piscator).
Verse 12: Now therefore go, and I will be (Is. 50:4; Jer. 1:9; Matt. 10:19; Mark 13:11; Luke 12:11, 12; 21:14, 15) with thy mouth, and teach thee what thou shalt say.
[I will be in thy mouth] I will make thee eloquent (Vatablus).
And teach thee what thou shalt say; by my Spirit to direct and assist thee what and how to speak. Whence Moses, though he still seems to have remained slow in speech, yet was in truth mighty in words as well as deeds, Acts 7:22. Compare Matthew 10:19, 20.
 Hebrew: וַיֹּ֙אמֶר מֹשֶׁ֣ה אֶל־יְהוָה֮ בִּ֣י אֲדֹנָי֒ לֹא֩ אִ֙ישׁ דְּבָרִ֜ים אָנֹ֗כִי גַּ֤ם מִתְּמוֹל֙ גַּ֣ם מִשִּׁלְשֹׁ֔ם גַּ֛ם מֵאָ֥ז דַּבֶּרְךָ אֶל־עַבְדֶּ֑ךָ כִּ֧י כְבַד־פֶּ֛ה וּכְבַ֥ד לָשׁ֖וֹן אָנֹֽכִי׃
 Hebrew: אִ֙ישׁ דְּבָרִ֜ים.
 Hebrew: גַּ֤ם מִתְּמוֹל֙ גַּ֣ם מִשִּׁלְשֹׁ֔ם.
 Exodus 4:10b: “…O my Lord (בִּ֣י אֲדֹנָי֒), I am not eloquent…”
 Genesis 43:20: “And said, O sir (בִּ֣י אֲדֹנִ֑י), we came indeed down at the first time to buy food…”
 Hebrew: לֹא֩ אִ֙ישׁ דְּבָרִ֜ים.
 Symmachus (second century) produced a Greek translation of the Old Testament, which survives only in fragments. Symmachus’ work is characterized by an apparent concern to render faithfully the Hebrew original, to provide a rendering consistent with the rabbinic exegesis of his time, and to set forth the translation in simple, pure, and elegant Septuagint-style Greek.
 Exodus 4:10b: “…but I am slow of speech, and of a slow tongue (כְבַד־פֶּ֛ה וּכְבַ֥ד לָשׁ֖וֹן).”
 Ezekiel 3:5, 6: “For thou art not sent to a people of a strange speech and of an hard language (וְכִבְדֵ֥י לָשׁ֖וֹן), but to the house of Israel; not to many people of a strange speech and of an hard language (וְכִבְדֵ֣י לָשׁ֔וֹן), whose words thou canst not understand. Surely, had I sent thee to them, they would have hearkened unto thee.”
 Hebrew: וַיֹּ֙אמֶר יְהוָ֜ה אֵלָ֗יו מִ֣י שָׂ֣ם פֶּה֮ לָֽאָדָם֒ א֚וֹ מִֽי־יָשׂ֣וּם אִלֵּ֔ם א֣וֹ חֵרֵ֔שׁ א֥וֹ פִקֵּ֖חַ א֣וֹ עִוֵּ֑ר הֲלֹ֥א אָנֹכִ֖י יְהוָֽה׃
 Exodus 4:11: “And the Lord said unto him, Who hath made (מִ֣י שָׂ֣ם) man’s mouth? or who maketh (מִי־יָשׂוּם) the dumb, or deaf, or the seeing, or the blind? have not I the Lord?”
 For example, Genesis 21:19a: “And God opened (וַיִּפְקַ֤ח אֱלֹהִים֙) her eyes, and she saw a well of water…”
 Hebrew: וְעַתָּ֖ה לֵ֑ךְ וְאָנֹכִי֙ אֶֽהְיֶ֣ה עִם־פִּ֔יךָ וְהוֹרֵיתִ֖יךָ אֲשֶׁ֥ר תְּדַבֵּֽר׃