Sahih (Sahih al-Bukhari)
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا خَالِدٌ ـ هُوَ ابْنُ عَبْدِ اللَّهِ ـ حَدَّثَنَا خَالِدٌ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ احْتَجَمَ النَّبِيُّ صلى الله عليه وسلم وَأَعْطَى الَّذِي حَجَمَهُ، وَلَوْ كَانَ حَرَامًا لَمْ يُعْطِهِ.
Narrated Ibn `Abbas:Once the Prophet (ﷺ) got his blood out (medically) and paid that person who had done it. If it had been illegal, the Prophet (ﷺ) would not have paid him