'Forty year' in the Bible

Thy raiment waxed not old upon thee, neither did thy feet swell this forty year.

And it came to pass, when he made mention of the ark of God, that [Eli] fell from off his seat backward by the side of the gate. And his neck broke, and he died, for he was an old man, and heavy. And he had judged Israel forty year

David was thirty years old when he became king, and he reigned forty years.

Joash was seven years old when he became king, and he reigned for forty years in Jerusalem. His mother’s name was Zibiah from Beersheba.

Now it was almost time for the Jewish Festival of Tabernacles [Note: This was also called "Festival of Shelters," and was one of three principal, annual Jewish festivals and commemorated the occasion of the Israelites living in tents or shelters during their forty year wandering in the desert].

But when a forty year time span was fulfilled by him, it came into his heart to go help his brothers, the sons of Israel.

And for about a forty-year time he was patient with them in the wilderness.