The Messenger of Allah ﷺ forbade the earnings of the cupper and the earnings of the female slave.
نهى رسول الله ﷺ عن كسب الحجام وكسب الأمة
Its chain of transmission is sahih. It was reported by Ibn Majah from Abu Masud, and by Suyuti in Jami Saghir, who indicated that it is a hasan hadith.