'Forty Years' in the Bible

And Solomon reigned in Jerusalem over all Israel forty years.

So king Rehoboam strengthened himself in Jerusalem, and reigned: for Rehoboam was one and forty years old when he began to reign, and he reigned seventeen years in Jerusalem, the city which the LORD had chosen out of all the tribes of Israel, to put his name there. And his mother's name was Naamah an Ammonitess.

Two and forty years old was he when he began to reign, and reigned one year in Jerusalem. His mother's name was Athaliah the daughter of Omri.

Joash was seven years old when he began to reign, and he reigned forty years in Jerusalem. His mother's name also was Zibiah of Beersheba.