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 23:16

23:16 So the three elite warriors broke through the Philistine forces and drew some water from the cistern in Bethlehem near the gate. They carried it back to David, but he refused to drink it. He poured it out as a drink offering to the Lord