1 Chronicles 6:12

After the exile in Babylon, the Judean community needed to confirm the legitimate ancestry of the priests. This genealogy of Kohath linked the ancestors from the Pentateuch to the high priests up to Judah's exile in 586 BC. Other records connected the priests after the exile to this lineage (see Ezra 3:2; 7:1–6; Haggai 1:1). Not all high priests were included in this list.

This section gives the family histories of the three main groups of the tribe of Levi:

1. The high priests (1 Chronicles 6:1–15)

2. The three clans of Levites (1 Chronicles 6:16–30)

3. The singers (1 Chronicles 6:31–47)

Each family history starts with an introduction and then lists the names.

This section highlights the importance of the priestly tribe of Levi due to its central position in the genealogical lists.

he it is that executed the priest's office in the temple that Solomon built in Jerusalem--It is doubtful whether the person in favor of whom this testimony is borne be Johanan or Azariah. If the former, he is the same as Jehoiada, who rendered important public services (2Ki. 11:1-20); if the latter, it refers to the worthy and independent part he acted in resisting the unwarrantable encroachments of Uzziah (Ch2 26:17).

in the temple that Solomon built in Jerusalem--described in this particular manner to distinguish it from the second temple, which was in existence at the time when this history was written.

The priests and Levites were more concerned than any other Israelites to preserve their pedigree clear and to be able to prove it, because all the honours and privileges of their office depended upon their descent. And we read of those who, though perhaps they really were children of the priests, yet, because they could not find the register of their genealogies, nor make out their descent by any authentic record, were, as polluted, put from the priesthood, and forbidden to eat of the holy things, Ezr 2:62, Ezr 2:63. It is but very little that is here recorded of the genealogies of this sacred tribe. I. The first fathers of it are here named twice, Ch1 6:1, Ch1 6:16. Gershom, Kohath, and Merari, are three names which we were very conversant with in the book of Numbers, when the families of the Levites were marshalled and had their work assigned to them. Aaron, and Moses, and Miriam, we have known much more of than their names, and cannot pass them over here without remembering that this was that Moses and Aaron whom God honoured in making them instruments of Israel's deliverance and settlement and figures of him that was to come, Moses as a prophet and Aaron as a priest. And the mention of Nadab and Abihu (though, having no children, there was no occasion to bring them into the genealogy) cannot but remind us of the terrors of that divine justice which they were made monuments of for offering strange fire, that we may always fear before him. 2. The line of Eleazar, the successor of Aaron, is here drawn down to the time of the captivity, Ch1 6:4-15. It begins with Eleazar, who came out of the house of bondage in Egypt, and ends with Jehozadak, who went into the house of bondage in Babylon. Thus, for their sins, they were left as they were found, which might also intimate that the Levitical priesthood did not make anything perfect, but this was to be done by the bringing in of a better hope. All these here named were not high priests; for, in the time of the judges, that dignity was, upon some occasion or other, brought into the family of Ithamar, of which Eli was; but in Zadok it returned again to the right line. Of Azariah it is here said (v. 10), He it is that executed the priest's office in the temple that Solomon built. It is supposed that this was that Azariah who bravely opposed the presumption of king Uzziah when he invaded the priest's office (Ch2 26:17, Ch2 26:18), though he ventured his neck by so doing. This was done like a priest, like one that was truly zealous for his God. He that thus boldly maintained and defended the priest's office, and made good its barriers against such a daring insult, might well be said to execute it; and this honour is put upon him for it; while Urijah, one of his successors, for a base compliance with King Ahaz, in building him an idolatrous altar, has the disgrace put upon him of being left out of this genealogy, as perhaps some others are. But some think that this remark upon this Azariah should have been added to his grandfather of the same name (Ch1 6:9), who was the son of Ahimaaz, and that he was the priest who first officiated in Solomon's temple. 3. Some other of the families of the Levites are here accounted for. One of the families of Gershom (that of Libni) is here drawn down as far as Samuel, who had the honour of a prophet added to that of a Levite. One of the families of Merari (that of Mahli) is likewise drawn down for several descents, Ch1 6:29, Ch1 6:30.

Johanan - Supposed to be the same as Jehoiada.
Executed the priest's office - Probably this refers to the dignified manner in which Azariah opposed King Uzziah, who wished to invade the priest's office, and offer incense in the temple. See Ch2 26:17, Ch2 26:18.

And the children of Amram, Aaron, and Moses, and Miriam,.... Very memorable persons: Aaron was the high priest, Moses the prophet and lawgiver, and Miriam a prophetess, see Micah 6:4,

the sons also of Aaron, Nadab and Abihu, Eleazar and Ithamar; the two first were destroyed by fire from heaven for offering strange fire, Leviticus 10:1 and the third succeeded his father in the high priesthood; the line of which is drawn from Aaron through him unto the Babylonish captivity, from hence to the end of the fifteenth verse, where it ends: Jehozadak is the same with Josedech, Haggai 1:1 who went young into Babylon, and whose son Joshua, born in the captivity, came out of it on the proclamation of Cyrus, Ezra 2:2. According to Josephus (e), and other Jewish writers (f), in the times of Uzzi, 1 Chronicles 6:6 the priesthood was translated into the family of Ithamar, of which Eli was the first high priest; where it continued to the times of Solomon, when it was restored to Zadok, of the line of Eleazar. It is particularly observed of Azariah, 1 Chronicles 6:10 that he it was that executed the priest's office in the temple built by Solomon; not that he was the first that officiated in it, that was Zadok; but this seems to be Azariah, who was the high priest in the times of Uzziah, who opposed him when he would have offered incense in the temple, 2 Chronicles 26:17, which may be the reason why he is so particularly taken notice of here; though some think this is to be understood of Johanan, the father of Azariah, supposed to the same with Jehoiada, who, in the times of Athaliah, was the instrument of preserving both church and state, 2 Kings 11:4, the temple in which he ministered is described as built by Solomon, because at the time of the writing of this there was another temple built, or building, by Zerubbabel.

(e) Antiqu. l. 5. c. 11. sect. 5. (f) Juchasin, fol. 136. 1.

The sons of Levi, Gershon, Kohath, and Merari. Which is repeated from Ch1 6:1 for the sake of their posterity, whose names are given in the three following verses, in the same manner as in Exo 6:17.
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1 Chronicles 6:20

ch1 6:20
ch1 6:20
ch1 6:20Of Gershon, Libni his son,.... Whose genealogy runs thus, Jahath, called Jehiel, Ch1 23:8. Zimmah, between whom was Shimei, Ch1 6:42. Joah, the same with Ethan, Ch1 6:42. Iddo, called Adaiah, Ch1 6:41. Zerah, Jeaterai, whose name was also Ethni, Ch1 6:41, the posterity of Shimei, the brother of Libni, are omitted.