Jeremiah 34:8-10

8The word that came unto Jeremiah from Jehovah, after that king Zedekiah had made a covenant with all the people that were at Jerusalem, to proclaim liberty unto them:

9that every man should let his bondman, and every man his bondmaid, the Hebrew and the Hebrewess, go free, that none should exact service of them, [that is,] of a Jew his brother.

10And all the princes and all the people that had entered into the covenant obeyed, every man letting his bondman and every man his bondmaid go free, that none should exact service of them any more: they obeyed, and let [them] go.