Jeremiah 34:8-11

The word that came to Jeremiah from the LORD, after King Zedekiah had made a covenant with all the people in Jerusalem to make a proclamation of liberty to them, that everyone should set free his Hebrew slaves, male and female, so that no one should enslave a Jew, his brother. And they obeyed, all the officials and all the people who had entered into the covenant that everyone would set free his slave, male or female, so that they would not be enslaved again. They obeyed and set them free. But afterward they turned around and took back the male and female slaves they had set free, and brought them into subjection as slaves.