Jeremiah 34:10-14

And all the officials and all the people obeyed who had entered into the covenant that each person was to set his male servant free and each his female servant, so that no one would keep them in bondage any longer; they obeyed, and set them free.

But afterward they turned around and took back the male servants and the female servants whom they had set free, and brought them into subjection as male servants and as female servants.

Then the word of the Lord came to Jeremiah from the Lord, saying,

“This is what the Lord, the God of Israel says: ‘I made a covenant with your forefathers on the day that I brought them out of the land of Egypt, from the house of bondage, saying,

“At the end of seven years each of you shall set free his Hebrew brother who has been sold to you and has served you for six years, and you shall send him out free from you.” But your forefathers did not obey Me nor incline their ear to Me.