The Feast of Sabbatical Year: The Seventy Years Captivity a Punishment for Neglecting

Those who escaped the sword were carried by Nebuchadnezzar into exile in Babylon, and they became servants to him and his sons until the kingdom of Persia came to power.

So the land enjoyed its Sabbath rest all the days of the desolation, until seventy years were completed, in fulfillment of the word of the LORD spoken through Jeremiah.