Jeremiah 34:7-9

King James Version

⁷ When the king of Babylon's army fought against Jerusalem, and against all the cities of Judah that were left, against Lachish, and against Azekah: for these defenced cities remained of the cities of Judah.

⁸ 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;

⁹ 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.