2 Samuel 15:7

15:7 After four years Absalom said to the king, “Let me go and repay my vow that I made to the Lord while I was in Hebron.

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.