'Seventy Years' in the Bible

So shall it be in that day, That Tyre shall be forgotten seventy years, According to the days of a certain king: At the end of seventy years, shall it befall Tyre according to the song of the harlot:

So shall it be, at the end of seventy years, That Yahweh will visit Tyre, And she will return to her hire, - Yea she will play the harlot - with all the kingdoms of the earth, upon the face of the ground.