2 Samuel 18:2

A third part. Armies are usually divided into three divisions: a centre and two wings when drawn up for battle; a van, the main body. and a rearguard when on the march. But the Israelites had no settled rule upon the point, and. when occasion required, Joab divided his army into two parts ( 2 Samuel 10:9 , 2 Samuel 10:10 ). The reason of the threefold division in this case was that Ittai had brought his clan, or taf, with him, and as these would certainly not have fought under an Israelite leader, nor the Israelites under Ittai, David placed all foreigners under his command, while he gave his own nephews the command of the native troops. He thus avoided all jealousies; and Ittai's men, honoured by being made a distinct portion of the army, would feel their reputation at stake, and would rival the Israelites in valour.