Chapter 28: The Book of Oaths
Hilal b. Yasaf reported that a person got angry and slapped his slave-girl. Thereupon Suwaid b. Muqarrin said to him: You could find no other part (to slap) but the prominent part of her face. See I was one of the seven sons of Muqarrin, and we had but only one slave-girl. The youngest of us slapped her, and Allah' s Messenger (ﷺ) commanded us to set her free. 2097
Sahih Muslim 1658b