2 Samuel 18:1-2

1David mustered the men who were with him and appointed over them commanders of thousands and commanders of hundreds.

2David sent out his troops, a third under the command of Joab, a third under Joab’s brother Abishai son of Zeruiah, and a third under Ittai the Gittite. The king told the troops, “I myself will surely march out with you.”