'Forty Years' in the Bible

The land had rest forty years. Othniel the son of Kenaz died.

"So let all your enemies perish, Yahweh, but let those who love him be as the sun when it rises forth in its strength." Then the land had rest forty years.

So Midian was subdued before the children of Israel, and they lifted up their heads no more. The land had rest forty years in the days of Gideon.

The children of Israel again did that which was evil in the sight of Yahweh; and Yahweh delivered them into the hand of the Philistines forty years.