Jeremiah 34:13-16

13Thus saith Jehovah, the God of Israel: I made a covenant with your fathers in the day that I brought them forth out of the land of Egypt, out of the house of bondage, saying, 14At the end of seven years ye shall let go every man his brother that is a Hebrew, that hath been sold unto thee, and hath served thee six years, thou shalt let him go free from thee: but your fathers hearkened not unto me, neither inclined their ear. 15And ye were now turned, and had done that which is right in mine eyes, in proclaiming liberty every man to his neighbor; and ye had made a covenant before me in the house which is called by my name: 16but ye turned and profaned my name, and caused every man his servant, and every man his handmaid, whom ye had let go free at their pleasure, to return; and ye brought them into subjection, to be unto you for servants and for handmaids.