Ash-Shama'il Al-Muhammadiyah, Book 49, Hadith 345 (English) ⓘ

Ibn 'Abbaas Radiyallahu 'Anhu said that Rasulullah Sallallahu 'Alayhi Wasallam took the treatment of cupping on both sides of his neck and between his shoulders, and paid the cupper his fees. If it had been haraam, he would not have paid it.

حَدَّثَنَا هَارُونُ بْنُ إِسْحَاقَ الْهَمْدَانِيُّ، قَالَ‏:‏ حَدَّثَنَا عَبْدَةُ، عَنْ سُفْيَانَ الثَّوْرِيِّ، عَنْ جَابِرٍ، عَنِ الشَّعْبِيِّ، عَنِ ابْنِ عَبَّاسٍ، قَالَ‏:‏ إِنَّ النَّبِيَّ صلى الله عليه وسلم احْتَجَمَ فِي الأَخْدَعَيْنِ، وَبَيْنَ الْكَتِفَيْنِ، وَأَعْطَى الْحَجَّامَ أَجْرَهُ، وَلَوْ كَانَ حَرَامًا لَمْ يُعْطِهِ‏.‏