'Forty' in the Bible

Isaac was forty years old when he married Rebekah, the daughter of Bethuel, the Aramean from Paddan-aram and sister of Laban the Aramean.

And so it was that forty years after Israel had demanded a king, Absalom asked the king, "Please let me go to Hebron so I can pay my vow that I made to the LORD,

Joash was seven years old when he began his reign, and he reigned forty years in Jerusalem. His mother's name was Zibiah. She was from Beer-sheba.

For forty years I loathed that generation, so I said, "They are a people whose hearts continuously err, and they have not understood my ways."