Albert Barnes Commentary 1 Chronicles 2

The sons of Israel - The order of the names here approximates an order determined by legitimacy of birth. A single change—the removal of Dan to the place after Benjamin—would give the following result:

1. The six sons of the first wife, Leah.
2. The two sons of the second wife, Rachel.
3. The two sons of the first concubine, Bilhah.
4. The two sons of the second concubine, Zilpah.

Dan’s undue prominence can perhaps be explained by his occupying the seventh place in the “blessing of Jacob” (Genesis 49:16).

The sons of Zerah - Here, for the first time, the writer of Chronicles draws from sources not otherwise known to us, recording facts not mentioned in the earlier Scriptures. Ethan, Heman, Calcol, and Dara, sons of Zerah, are only known to us from this passage, since there are no sufficient grounds for identifying them with the “sons of Mahol” (marginal reference).

The name “Achan” (Joshua 7:1) appears to have been changed to “Achar” to more closely assimilate it with the Hebrew word for “troubler.” From the time of his sin, this was regarded as the true meaning of his name (Joshua 7:25–26).

David the seventh - Jesse had eight sons, of whom David was the youngest (1 Samuel 16:10–11; 1 Samuel 17:12). Probably one of the sons shown to Samuel at Bethlehem did not grow up.

Sisters - that is, half-sisters. Abigail and Zeruiah were not daughters of Jesse, but of a certain Nahash, whose widow Jesse married (2 Samuel 17:25).

From the present passage, and from the fact that Abishai joined David as a comrade-in-arms before Joab (1 Samuel 26:6), it would seem that although Joab was preeminent among the three (2 Samuel 2:13, 16), Abishai was the eldest.