'Forty' in the Bible

Ish-bosheth, Saul's son, was forty years old when he began to reign over Israel, and he reigned two years. But the house of Judah followed David.

David was thirty years old when he began to reign, and he reigned forty years.

And the Syrians fled before Israel; and David slew of the Syrians the men of'seven hundred chariots, and forty thousand horsemen, and smote Shobach the captain of their host, so that he died there.

And it came to pass at the end of forty years, that Absalom said unto the king, I pray thee, let me go and pay my vow, which I have vowed unto Jehovah, in Hebron.