Sahih (Sahih al-Bukhari)
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، عَنْ خَالِدٍ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ احْتَجَمَ النَّبِيُّ صلى الله عليه وسلم وَأَعْطَى الْحَجَّامَ أَجْرَهُ، وَلَوْ عَلِمَ كَرَاهِيَةً لَمْ يُعْطِهِ.
Narrated Ibn `Abbas:When the Prophet (ﷺ) was cupped, he paid the man who cupped him his wages. If it had been undesirable he would not have paid him