Passed on - Rather, “crossed” the Brook Kidron, as in 2 Samuel 15:22-23.
Gittites - During David’s residence in the country of the Philistines he attached such a band to himself; and after the settlement of his kingdom, and the subjugation of the Philistines, the band received recruits from Gath, perhaps with the king of Gath’s consent. They were now under the command of Ittai the Gittite, a foreigner 2 Samuel 15:19, and “his brethren” 2 Samuel 15:20. The number 600 probably indicates that this band or regiment of Gittites had its origin in David’s band of 600 1 Samuel 23:13; 1 Samuel 27:2. They were at first, it is likely, all Israelites, then Gittites mixed with Israelites, and at last all Gittites.