Jeremiah 34:15-16

And ye were now turned, and had done right in my sight, in proclaiming liberty every man to his neighbour; and ye had made a covenant before me in the house which is called by my name: but ye turned and polluted my name, and caused every man his servant, and every man his handmaid, whom he had set at liberty at their pleasure, to return, and brought them into subjection, to be unto you for servants and for handmaids.