2 Samuel 15:6-9
English Standard Version
7And at the end of four years Absalom said to the king, "Please let me go and pay my vow, which I have vowed to the Lord, in Hebron.
8For your servant vowed a vow while I lived at Geshur in Aram, saying, ‘If the Lord will indeed bring me back to Jerusalem, then I will offer worship to the Lord.’"
9The king said to him, "Go in peace." So he arose and went to Hebron.