Jeremiah 34:8-11

8The word came to Jeremiah from the Lord after King Zedekiah had made a covenant (solemn pledge) with all the [Hebrew] people who were [slaves] in Jerusalem to proclaim liberty to them:

9that every man should let his Hebrew slaves, male and female, go free, so that no one should make a slave of a Jew, his brother.

10So all the princes and all the people who had entered into the covenant agreed that everyone would let his male servant and his female servant go free, and that no one would keep them in bondage any longer; they obeyed, and set them free.

11But afterward they backed out [of the covenant] and made the male servants and the female servants whom they had set free return [to them], and brought the male servants and the female servants again into servitude.