It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that once the Prophet (peace and blessings be upon him) called (a slave of Banu Bayadah, and he) performed cupping. The Prophet (peace and blessings be upon him) gave him (one and a half mudd of wheat as) wages. If this wage had been unlawful, the Prophet (peace and blessings be upon him) would never have given it to him.
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 3085