Sahih Muslim 4302
صحيح مسلم#4302SahihHilal 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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 27:49