مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3210
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) said: "When one of you eats food, let him not wipe his hand with a cloth until he has licked it or had it licked for him.”
Musnad Ahmad 3234|Its isnad is saheeh, al-Bukhari (5456) and Muslim (2031)]