It is narrated from Sayyiduna Muhayyisa (may Allah be pleased with him) that he asked the Messenger of Allah (peace and blessings be upon him) about cupping, so the Prophet (peace and blessings be upon him) forbade him from it. But he kept repeatedly seeking permission from the Prophet until the Prophet (peace and blessings be upon him) said: "(The money earned from it) feed it to your slave or spend it on the fodder for your camel."
Hadith Referenceالسنن المأثورة / باب في البيوع / 266
Hadith Takhrijمسند حمیدی: 387/2، رقم: 878، مسند احمد: 100/39، رقم: 23693 وقال الارنوؤط حدیث صحیح رجالہ ثقات، مصنف ابن ابی شیبہ: 265/6، شرح معانی الآثار للطحاوی: 131/4