With the help of Zadok of the sons of Eleazar, and Ahimelech of the sons of Ithamar, David organized them according to the appointed duties in their service.
The particular account of these establishments is of little use to us now; but, when Ezra published it, it was of great use to direct their church affairs after their return from captivity into the old channel again. The title of this record we have v.
Commenting on 1 Chronicles 24:1-19
And David distributed them,.... The posterities of Eleazar and Ithamar into certain classes or courses: both Zadok of the sons of Eleazar, and Ahimelech of the sons of Ithamar; these were the two principal men of the respective families, the one was high priest, and the other "sagan" or deputy; or they both officiated as high priests alternately, until the one was removed in Solomon's...
Zadok . . . and Ahimelech of the sons of Ithamar--This statement, taken in connection with Ch1 24:6, is not a little perplexing, since (Sa2 15:24, Sa2 15:35; Sa2 20:25) Abiathar is mentioned as the person conjoined in David's time with Zadok, in the collegiate exercise of the high priesthood. Some think that the words have been transposed, reading Abiathar, the son of Ahimelech.