Sunan Abī Dāwūd 3423✓ 5Sahih
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، حَدَّثَنَا خَالِدٌ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ احْتَجَمَ رَسُولُ اللَّهِ صلى الله عليه وسلم وَأَعْطَى الْحَجَّامَ أَجْرَهُ وَلَوْ عَلِمَهُ خَبِيثًا لَمْ يُعْطِهِ .
Narrated Ibn 'Abbas: The Messenger of Allah (ﷺ) got him self cupped and gave the cupper his wages. Had he considered it impure, he would not have given it (wage) to him