2Sa 20:8 “When they were by the great stone at Gibeon, and Amasa came to meet them (there), Joab was girded with his armour-coat as his clothing, and the girdle of the sword was bound over it upon his loins in its sheath, which came out, and it fell (i.e., the sheath came out of the sword-belt in which it was fastened, and the sword fell to the ground), Joab said to Amasa,” etc. The eighth verse contains only circumstantial clauses, the latter of which (from ויואב onwards) are subordinate to the earlier ones, so that ויּאמר (2Sa 20:9) is attached to the first clause, which describes the meeting between the advancing army and Amasa.
There is something striking, however, in the fact that Joab appears among them, and indeed, as we see from what follows, as the commander of the forces; for according to 2Sa 20:6, David had commissioned Abishai, Joab’s brother, to pursue Sheba, and even in 2Sa 20:7 Joab’s men only are mentioned. This difficulty can hardly be solved in any other manner than by the simple assumption that David had told Abishai to go out with Joab, and that this circumstance is passed over in the brief account in 2Sa 20:6, in which the principal facts alone are given, and consequently the name of Joab does not occur there. Clericus adopts the following explanation. “Mention,” he says, “has hitherto been made simply of the command given to Abishai, but this included an order to Joab to go as well; and there is nothing to preclude the supposition that Joab’s name was mentioned by the king, although this is not distinctly stated in the brief account before us.”