2 Chronicles 36:20-21

He deported to Babylon those who had escaped from the sword; and they were servants to him and to his sons until the kingdom of Persia was established there, to fulfill the word of the LORD by the mouth of Jeremiah, until the land had restored its Sabbaths; for as long as the land lay desolate it kept Sabbath until seventy years were complete. [Lev 25:4; 26:43; Jer 25:11; 29:10]