Adam Clarke on 1 Chronicles 27:34

And after Ahithophel - The Targum is curious: "When they went to war, they asked counsel of Ahithophel; and, after the counsel of Ahithophel, they inquired by Urim and Thummim of Jehoiada, the son of Benaiah, prince of the Sanhedrin, and chief of the priesthood; and from Abiathar, the high priest. And after they had inquired by Urim and Thummim, they went out to battle, well armed with bows and slings; and Joab, the general of the king's troops, led them on." It is worthy of remark, that Obil, an Ishmaelite or Arab, was put over the camels, which is a creature of Arabia; and that Jaziz, a Hagarene, (the Hagarenes were shepherds by profession), was put over the flocks: nothing went by favor; each was appointed to the office for which he was best qualified; and thus men of worth were encouraged, and the public service effectually promoted.