1 Then the LORD said unto Moses, Now shalt thou see what I will do to Pharaoh: for with a strong hand shall he let them go, and with a strong hand shall he drive them out of his land. 2 And God spake unto Moses, and said unto him, I am the LORD: 3 And I appeared unto Abraham, unto Isaac, and unto Jacob, by the name of God Almighty, but by my name JEHOVAH was I not known to them. 4 And I have also established my covenant with them, to give them the land of Canaan, the land of their pilgrimage, wherein they were strangers. 5 And I have also heard the groaning of the children of Israel, whom the Egyptians keep in bondage; and I have remembered my covenant. 6 Wherefore say unto the children of Israel, I am the LORD, and I will bring you out from under the burdens of the Egyptians, and I will rid you out of their bondage, and I will redeem you with a stretched out arm, and with great judgments: 7 And I will take you to me for a people, and I will be to you a God: and ye shall know that I am the LORD your God, which bringeth you out from under the burdens of the Egyptians. 8 And I will bring you in unto the land, concerning the which I did swear to give it to Abraham, to Isaac, and to Jacob; and I will give it you for an heritage: I am the LORD. 9 And Moses spake so unto the children of Israel: but they hearkened not unto Moses for anguish of spirit, and for cruel bondage. 10 And the LORD spake unto Moses, saying, 11 Go in, speak unto Pharaoh king of Egypt, that he let the children of Israel go out of his land. 12 And Moses spake before the LORD, saying, Behold, the children of Israel have not hearkened unto me; how then shall Pharaoh hear me, who am of uncircumcised lips? 13 And the LORD spake unto Moses and unto Aaron, and gave them a charge unto the children of Israel, and unto Pharaoh king of Egypt, to bring the children of Israel out of the land of Egypt. 14 These be the heads of their fathers' houses: The sons of Reuben the firstborn of Israel; Hanoch, and Pallu, Hezron, and Carmi: these be the families of Reuben. 15 And the sons of Simeon; Jemuel, and Jamin, and Ohad, and Jachin, and Zohar, and Shaul the son of a Canaanitish woman: these are the families of Simeon. 16 And these are the names of the sons of Levi according to their generations; Gershon, and Kohath, and Merari: and the years of the life of Levi were an hundred thirty and seven years. 17 The sons of Gershon; Libni, and Shimi, according to their families. 18 And the sons of Kohath; Amram, and Izhar, and Hebron, and Uzziel: and the years of the life of Kohath were an hundred thirty and three years. 19 And the sons of Merari; Mahali and Mushi: these are the families of Levi according to their generations. 20 And Amram took him Jochebed his father's sister to wife; and she bare him Aaron and Moses: and the years of the life of Amram were an hundred and thirty and seven years. 21 And the sons of Izhar; Korah, and Nepheg, and Zichri. 22 And the sons of Uzziel; Mishael, and Elzaphan, and Zithri. 23 And Aaron took him Elisheba, daughter of Amminadab, sister of Naashon, to wife; and she bare him Nadab, and Abihu, Eleazar, and Ithamar. 24 And the sons of Korah; Assir, and Elkanah, and Abiasaph: these are the families of the Korhites. 25 And Eleazar Aaron's son took him one of the daughters of Putiel to wife; and she bare him Phinehas: these are the heads of the fathers of the Levites according to their families. 26 These are that Aaron and Moses, to whom the LORD said, Bring out the children of Israel from the land of Egypt according to their armies. 27 These are they which spake to Pharaoh king of Egypt, to bring out the children of Israel from Egypt: these are that Moses and Aaron. 28 And it came to pass on the day when the LORD spake unto Moses in the land of Egypt, 29 That the LORD spake unto Moses, saying, I am the LORD: speak thou unto Pharaoh king of Egypt all that I say unto thee. 30 And Moses said before the LORD, Behold, I am of uncircumcised lips, and how shall Pharaoh hearken unto me?
[AD 339] Eusebius of Caesarea on Exodus 6:3
It will naturally be asked how he that is beyond the universe, himself the only almighty God, appeared to the fathers. And the answer will be found if we realize the accuracy of Holy Scripture. For the Septuagint rendering, “I was seen of Abraham, Isaac and Jacob, being their God,” Aquila says, “And I was seen by Abraham, Isaac and Jacob as a sufficient God,” clearly showing that the almighty God himself, who is one, was not seen in his own person and that he did not give answers to the fathers, as he did to Moses by an angel, or a fire or a bush, but “as a sufficient God.” Thus the Father was seen by the fathers through the Son, according to his saying in the Gospels, “He that has seen me has seen the Father.” For the knowledge of the Father was revealed in him and by him. But in cases when he appeared to save men, he was seen in the human form of the Son, giving an earnest before the time to the godly of that salvation which should come through him to all men. But when he was going to be the avenger and chastiser of the wicked Egyptians, he appeared no longer as a sufficient God but as an angel ministering punishment, and in form of fire and flame, ready at once to devour them like wild and thorny undergrowth. So they say that the bush darkly refers to the wild, savage and cruel character of the Egyptians and the fire to the avenging power of the chastisement that overtook them.

[AD 585] Cassiodorus on Exodus 6:3
The God of gods is the Lord Christ; with the Father and Holy Spirit he is truly called God of gods, though the title is not wholly appropriate to the Godhead because the human tongue cannot, as we have already said, indicate the height of the Godhead beyond this. Deus (“God”) in the Greek language means “fear,” and since he alone is to be feared the word attained the role of a title. We read in Exodus: “My name Adonai I did not show them.” From this we are to realize that the name is secret and is known to have been revealed not even to chosen ministers. So he spoke through prophets, through apostles and more powerfully through his own mouth.

[AD 1781] Richard Challoner on Exodus 6:3
My name Adonai: The name, which is in the Hebrew text, is that most proper name of God, which signifieth his eternal, self-existent being, Ex. 3. 14, which the Jews out of reverence never pronounce; but, instead of it, whenever it occurs in the Bible, they read Adonai, which signifies the Lord; and, therefore, they put the points or vowels, which belong to the name Adonai, to the four letters of that other ineffable name Jod, He, Vau, He. Hence some moderns have framed the name Jehovah, unknown to all the ancients, whether Jews or Christians; for the true pronunciation of the name, which is in the Hebrew text, by long disuse, is now quite lost.
[AD 1781] Richard Challoner on Exodus 6:12
Uncircumcised lips: So he calls the defect he had in his words, or utterance.
[AD 430] Augustine of Hippo on Exodus 6:14
There is no doubt that this is a mysterious passage. The Scripture wishes to demonstrate the origin of Moses, because his action now required it. His descent began from the firstborn of Jacob, that is, Reuben, and then to Simeon, and then to Levi. It went no further, because Moses was descended from Levi. These men who are mentioned here had already been mentioned among the seventy-five men in whom Israel entered Egypt. For God did not want the first or the second tribe, but the third—that is, the tribe of Levi—to be the priestly tribe.

[AD 253] Origen of Alexandria on Exodus 6:24
For though there were three sons of Korah whose names we find in the book of Exodus—Aser, which is, by interpretation, “instruction,” and the second Elkana, which is translated “possession of God,” and the third Abiasaph, which in the Greek tongue might be rendered “congregation of the father”—yet the prophecies were not divided but were both spoken and written by one spirit and one voice and one soul, which worked in true harmony. And the three speak as one, “As the hart pants after the springs of the water, so pants my soul after you, O God.”

[AD 430] Augustine of Hippo on Exodus 6:30
Moses says, “Behold, I have a weak voice, how will Pharaoh listen to me?” He appears to excuse himself for the weakness of his voice, not only due to the great number of the people but also due to the condition of one man. It would be remarkable if his voice were so weak that he could not be heard even by one man. Or perhaps the royal dignity did not allow them to speak at close range? For God says to Moses, “Behold, I gave you as a god to Pharaoh, and Aaron your brother will be your prophet.”