مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2956
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, he would not have given it to him. He was treated with cupping in the veins at the side of the neck and between the shoulders. He was treated with cupping by a slave of Banu Bayadah. One and a half mudds were taken from him every day, but the Prophet (ﷺ) intercede for him with his masters, and they made it one mudd.
Musnad Ahmad 2979A saheeh hadeeth; this is a da'eef isnad]