Al-Adab Al-Mufrad #178

Mu'awiya ibn Muqarrin said, "I slapped a mawla of mine and he fled. Then my father called me and said, 'I will tell you a story. We, the sons of Muqarrin, were seven, and we had one servant. Then one of us slapped her and that was mentioned to the Messenger of Allah, may Allah bless him and grant him peace. He said, 'Order them to set her free.' The Prophet, may Allah bless him and grant him peace, was told. 'She is the only servant they have.' He said, 'Then let them hire her and when they no longer need her, let her go on her way.'"