The Messenger of Allah ﷺ forbade us from naming our slaves by four names, Aflah, Rabah, Yasar, and Nafi.
نهانا رسول الله ﷺ أن نسمي رقيقنا بأربعة أسماء: أفلح، ورباح، ويسار، ونافع.
Muslim narrated it in "Manners" (2136:10) via Mutamir bin Sulayman, who said, "I heard Rukayn narrating from his father, from Samura bin Jundab," who said, then he mentioned it.