2 Samuel 15:7-9
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.
15:8 For I made this vow when I was living in Geshur in Aram: ‘If the Lord really does allow me to return to Jerusalem, I will serve the Lord.’”
15:9 The king replied to him, “Go in peace.” So Absalom got up and went to Hebron.