مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2579
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn 'Abbas (رضي الله عنه) that The Messenger of Allah (ﷺ) was treated with cupping when he was fasting.
Musnad Ahmad 2594Its isnad is saheeh]