'Seventy Years' in the Bible

And all this land hath been for a waste, for an astonishment, and these nations have served the king of Babylon seventy years.

And it hath come to pass, at the fulness of seventy years, I charge against the king of Babylon, and against that nation -- an affirmation of Jehovah -- their iniquity, and against the land of the Chaldeans, and have appointed it for desolations age-during.

For thus said Jehovah, Surely at the fulness of Babylon -- seventy years -- I inspect you, and have established towards you My good word, to bring you back unto this place.