2 Samuel 14:26

14:26 When he would shave his head – at the end of every year he used to shave his head, for it grew too long and he would shave it – he used to weigh the hair of his head at three pounds according to the king’s weight.

2 Samuel 18:2

18:2 David then sent out the army – a third under the leadership of Joab, a third under the leadership of Joab’s brother Abishai son of Zeruiah, and a third under the leadership of Ittai the Gittite. The king said to the troops, “I too will indeed march out with you.”