Jeremiah 34:12

10All the princes and all the people obeyed who had entered into the covenant, that everyone should let his male servant and everyone his female servant go free, that no one should make bondservants of them any more. They obeyed and let them go,

11but afterwards they turned, and caused the servants and the handmaids whom they had let go free to return, and brought them into subjection for servants and for handmaids.

12Therefore the LORD’s word came to Jeremiah from the LORD, saying,

13“The LORD, the God of Israel, says: ‘I made a covenant with your fathers in the day that I brought them out of the land of Egypt, out of the house of bondage, saying:

14At the end of seven years, every man of you shall release his brother who is a Hebrew, who has been sold to you, and has served you six years. You shall let him go free from you. But your fathers didn’t listen to me, and didn’t incline their ear.