Adam Clarke on 1 Samuel 13:2

Two thousand were with Saul - Saul, no doubt, meditated the redemption of his country from the Philistines; and having chosen three thousand men, he thought best to divide them into companies, and send one against the Philistine garrison at Michmash, another against that at Beth-el, and the third against that at Gibeah: he perhaps hoped, by surprising these garrisons, to get swords and spears for his men, of which we find, (1Sam 13:22), they were entirely destitute.