Jeremiah 25:11-12

11 This whole land shall become a ruin and a waste, and these nations shall serve the king of Babylon seventy years. 12 Then after seventy years are completed, I will punish the king of Babylon and that nation, the land of the Chaldeans, for their iniquity, declares the Lord, making the land an everlasting waste.

Jeremiah 29:10

10 “For thus says the Lord: When seventy years are completed for Babylon, I will visit you, and I will fulfill to you my promise and bring you back to this place.