2 Samuel 15
7 Ref It happened at the end of forty years, that Absalom said to the king, please let me go and pay my vow, which I have vowed to Yahweh, in Hebron.
8 Ref For your servant vowed a vow while I abode at Geshur in Syria, saying, If Yahweh shall indeed bring me again to Jerusalem, then I will serve Yahweh.