Mukhtasar Bukhari (Abridged) 1046 — Sin of selling a free person

Narrated by Sayyiduna Abu Hurairah (may Allah be pleased with him) from the Noble Prophet (peace and blessings of Allah be upon him) that he said: "There are three persons for whom I will be an opponent on the Day of Resurrection: (1) The person who makes a covenant in My name and then breaks it; (2) The person who sells a free man and consumes his price; (3) The person who hires a laborer, gets the full work done from him, and then does not pay his wages."