'Seventy Years' in the Bible

All this land was for a waste, for a desolation, and these nations served the king of Babel seventy years.

And it was when seventy years were filled up, I will review over the king of Babel and upon this nation, says Jehovah, their iniquity, and upon the land of the Chaldeans, and I set it for eternal desolations

For thus said Jehovah, That according to the filling up to Babel of seventy years I will review you and lift up to you my good word to turn you back to this place.