I. We have here a genealogy, not an endless one, such as the apostle condemns (Ti1 1:4), for it ends in those two great patriots Moses and Aaron, and comes in here to show that they were Israelites, bone of their bone and flesh of their flesh whom they were sent to deliver, raised up unto them of their brethren, as Christ also should be, who was to be the prophet and priest, the Redeemer and lawgiver, of the people of Israel, and whose genealogy also, like this, was to be carefully preserved. The heads of the houses of three of the tribes are here named, agreeing with the accounts we had, Gen. 46. Dr. Lightfoot thinks that Reuben, Simeon, and Levi, are thus dignified here by themselves for this reason, because they were left under marks of infamy by their dying father, Reuben for his incest and Simeon and Levi for their murder of the Shechemites; and therefore Moses would put this particular honour upon them, to magnify God's mercy in their repentance and remission, as a pattern to those that should afterwards believe: the two former seem rather to be mentioned only for the sake of a third, which was Levi, from whom Moses and Aaron descended, and all the priests of the Jewish church. Thus was the tribe of Levi distinguished betimes. Observe here, 1. That Kohath, from whom Moses and Aaron, and all the priests, derived their pedigree, was a younger son of Levi, Exo 6:16. Note, The grants of God's favours do not go by seniority of age and priority of birth, but the divine sovereignty often prefers the younger before the elder, so crossing hands. 2. That the ages of Levi, Kohath, and Amram, the father, grandfather, and great grandfather, of Moses, are here recorded; they all lived to a great age, Levi to 137, Kohath to 133, and Amram to 137. Moses himself came much short of them, and fixed seventy or eighty for the ordinary stretch of human life (Psa 90:10); for now that God's Israel was multiplied and had become a great nation, and divine revelation was by the hand of Moses committed to writing and no longer trusted to tradition, the two great reasons for the long lives of the patriarchs had ceased, and therefore henceforward fewer years must serve men. 3. That Aaron married Elisheba (the same name with that of the wife of Zecharias, Elizabeth, as Miriam is the same with Mary), daughter of Amminadab, one of the chief of the fathers of the tribe of Judah; for the tribes of Levi and Judah often intermarried, Exo 6:23. 4. It must not be omitted that Moses has recorded the marriage of his father Amram with Jochebed his own aunt (Exo 6:20); and it appears by Num 26:59 that it must be taken strictly for his father's own sister, at least by the half blood. This marriage was afterwards forbidden as incestuous (Lev 18:12), which might be looked upon as a blot upon his family, though before that law; yet Moses does not conceal it, for he sought not his own praise, but wrote with a sincere regard to truth, whether it smiled or frowned upon him. 5. He concludes it with a particular mark of honour on the persons he is writing of, though he himself was one of them, Exo 6:26, Exo 6:27. These are that Moses and Aaron whom God pitched upon to be his plenipotentiaries in this treaty. These were those to whom God spoke (Exo 6:26), and who spoke to Pharaoh on Israel's behalf, Exo 6:27. Note, Communion with God and serviceableness to his church are things that, above any other, put true honour upon men. Those are great indeed with whom God converses and whom he employs on his service. Such were that Moses and Aaron; and something of this honour have all his saints, who are made to our God kings and priests.
II. In the close of the chapter Moses returns to his narrative, from which he had broken off somewhat abruptly (Exo 6:13), and repeats, 1. The charge God had given him to deliver his message to Pharaoh (Exo 6:29): Speak all that I say unto thee, as a faithful ambassador. Note, Those that go on God's errand must not shun to declare the whole counsel of God. 2. His objection against it, Exo 6:30. Note, Those that have at any time spoken unadvisedly with their lips ought often to reflect upon it with regret, as Moses seems to do here.

His father's sister - דדתו dodatho. The true meaning of this word is uncertain. Parkhurst observes that דוד dod signifies an uncle in Sa1 10:14; Lev 10:4, and frequently elsewhere. It signifies also an uncle's son, a cousin-german: compare Jer 32:8 with Exo 6:12, where the Vulgate renders דדי dodi by patruelis mei, my paternal cousin; and in Amo 6:10, for דודו dodo, the Targum has קריביה karibiah, his near relation. So the Vulgate, propinquus ejus, his relative, and the Septuagint, οἱ οικειοι αυτων, those of their household. The best critics suppose that Jochebed was the cousin-german of Amram, and not his aunt. See Clarke's note on Exo 2:1.
Bare him Aaron and Moses - The Samaritan, Septuagint, Syriac, and one Hebrew MS. add, And Miriam their sister. Some of the best critics suppose these words to have been originally in the Hebrew text.

And Aaron took him Elisheba,.... The same name we pronounce Elizabeth; and of this name was the wife of Zacharias, the father of John the Baptist, Luk 1:5, this woman Aaron took was

the daughter of Amminadab, the sister of Naashon; a prince of the tribe of Judah, Num 7:12, her he took to wife; or married; for though intermarriages with the several tribes were not allowed, nor used in after times, that they might be kept distinct, and the inheritances also, yet the tribe of Levi often took wives of other tribes, because they had no inheritance, and were to have none in the land of Canaan, so that confusion in tribes and inheritance was not made hereby; and it is observable, that these marriages were frequently with the tribe of Judah, as signifying the union of the kingly and priestly offices in Christ, who sprung from the tribe of Judah:

and she bare him Nadab, and Abihu, Eleazar, and Ithamar; the two first of these died by fire from heaven in their father's lifetime, for offering strange fire to the Lord, Lev 10:1. Eleazar succeeded his father in the priesthood, Num 20:26 and of the sons of Ithamar executing the priest's office, see Ch1 24:2.

Amram took him Jochebed his father's sister to wife--The Septuagint and Syriac versions render it "his cousin."