Sahih Muslim 2650
صحيح مسلم#2650SahihQais b Sakan reported that al-Ash'ath b. Qais went to 'Abdullah on the day of 'Ashura while he was eating. He said:Abu Muhammad, come near and dine. Upon this he said: I am fasting. Thereupon he said: We used to observe fast and then (this practice) was abandoned
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 13:156