He sent out the troops, a third under Joab, a third under Joab’s brother Abishai son of Zeruiah, and a third under Ittai the Gittite. And the king said to the troops, “I will surely march out with you as well.”
Jewish Publication Society of America Version (JPS1917) - 2 Samuel 18:2 >And David sent forth the people, a third part under the hand of Joab, and a third part under the hand of Abishai the son of Zeruiah, Joab's brother, and a third part under the hand of Ittai the Gittite. And the king said unto the people: 'I will surely go forth with you myself also.'