Cross reference
Judges 3:30
30 and Moab is humbled in that day under the hand of Israel; and the land resteth eighty years.
Judges 3:11
11 and the land resteth forty years. And Othniel son of Kenaz dieth,
Judges 5:31
31 So do all Thine enemies perish, O Jehovah, And those loving Him `are' As the going out of the sun in its might!' and the land resteth forty years.