Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: The Messenger of Allah (peace and blessings be upon him) had himself cupped and gave the cupper his wage, and had he (peace and blessings be upon him) considered it impure, he would not have given it.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11904