مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3060
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn ‘Abbas (رضي الله عنه) said: The Messenger of Allah (ﷺ) was treated with cupping and he gave the cupper his fee. If it was haram, the Messenger of Allah (ﷺ) would not have given it to Him.
Musnad Ahmad 3085Its isnad is saheeh]