Sahih Muslim , Book 13, Hadith 155 (In-Book) ⓘ
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 aban- doned it (the practice of observing fast on Ashura).
وَحَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، وَعُثْمَانُ بْنُ أَبِي شَيْبَةَ، قَالاَ حَدَّثَنَا جَرِيرٌ، عَنِ الأَعْمَشِ، بِهَذَا الإِسْنَادِ وَقَالاَ فَلَمَّا نَزَلَ رَمَضَانُ تَرَكَهُ .
also referenced under: Hadith 1127 (Reference) & Book 6, Hadith 2511 (USC-MSA)