Jeremiah 34:8-9

{This is} the word that came unto Jeremiah from the LORD, after that the king Zedekiah had made a covenant with all the people which {were} at Jerusalem, to proclaim liberty unto them; That every man should let his manservant, and every man his maidservant, {being} an Hebrew or an Hebrewess, go free; that none should serve himself of them, {to wit}, of a Jew his brother.