2 Samuel 15:7

15:7 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.
-World English Bible

Other Translation

15:7 And it came to pass after forty years, that Absalom said unto the king, I pray thee, let me go and pay my vow, which I have vowed unto the LORD, in Hebron.
-King James Version