Sayyidah Aisha (may Allah be pleased with her) says that my mukatab (contracted slave) came to me with the remaining portion of his contract. I said to him: After this time, you cannot enter upon me (because you are now free). So strive in the way of Allah, for I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever's heart is touched by dust in the way of Allah, Allah makes the Fire forbidden for him."