ENOfficial
Jabir b. Samura said, “God’s messenger used to command us to observe the day of ‘Ashura’ as a fast, urge us to observe it and pay attention to us when it came; but when Ramadan was made obligatory he neither commanded nor forbade us to observe it, nor did he pay attention to us when it came.” Muslim transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ جَابِرِ بْنِ سَمُرَةَ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَأْمُرُ بِصِيَامِ يَوْمِ عَاشُورَاءَ وَيَحُثُّنَا عَلَيْهِ وَيَتَعَاهَدُنَا عِنْدَهُ فَلَمَّا فُرِضَ رَمَضَانُ لَمْ يَأْمُرْنَا وَلَمْ يَنْهَنَا عَنْهُ وَلم يتعاهدنا عِنْده. رَوَاهُ مُسلم
sunnah.com