مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3026
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) drank some milk, then he called for water and rinsed out is his mouth, and he said: "It is somewhat greasy.”
Musnad Ahmad 3050A saheeh hadeeth]