ENOfficial
It was narrated that Silah bin Zufar said: “We were with ‘Ammar on the day concerning which there was some doubt. A (roasted) sheep was brought and some of the people moved away. ‘Ammar said: ‘Whoever is fasting on this day has disobeyed Abu Qasim (ﷺ).’”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، حَدَّثَنَا أَبُو خَالِدٍ الأَحْمَرُ، عَنْ عَمْرِو بْنِ قَيْسٍ، عَنْ أَبِي إِسْحَاقَ، عَنْ صِلَةَ بْنِ زُفَرَ، قَالَ كُنَّا عِنْدَ عَمَّارٍ فِي الْيَوْمِ الَّذِي يُشَكُّ فِيهِ فَأُتِيَ بِشَاةٍ فَتَنَحَّى بَعْضُ الْقَوْمِ فَقَالَ عَمَّارٌ مَنْ صَامَ هَذَا الْيَوْمَ فَقَدْ عَصَى أَبَا الْقَاسِمِ ـ صلى الله عليه وسلم ـ .
sunnah.com