Sahih Muslim | Book 6 | Hadith Number 2511

Narrated by Jarir
This hadith has been narrated from Jarir on the authority of A'mash with the same chain of transmitters and he said (these words with a little bit of variation from the previous hadith): When (fasting) in Ramadan was (made) obligatory, he abandoned it (the practice of observing fast on Ashura).