2 Samuel 18:1-2

1David brought together all the men who were with him. He chose some officers to lead groups of 1,000 soldiers, and some to lead groups of 100 soldiers.

2David sent his army out in three groups. Joab led one group. Joab's brother Abishai, Zeruiah's son, led another group. Ittai from Gath led the third group. The king said to them all, ‘I myself will go with you into battle.’