Narrated by:Silah said
It was narrated that Silah said:"We were with 'Ammar and a roast sheep was brought and he said: 'Eat.' One of the people turned away and said: 'I am fasting 'Ammar said: Whoever fasts on the day concerning which there is doubt, has disobeyed Abu Al-Qasim."' '
أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ سَعِيدٍ الأَشَجُّ، عَنْ أَبِي خَالِدٍ، عَنْ عَمْرِو بْنِ قَيْسٍ، عَنْ أَبِي إِسْحَاقَ، عَنْ صِلَةَ، قَالَ كُنَّا عِنْدَ عَمَّارٍ فَأُتِيَ بِشَاةٍ مَصْلِيَّةٍ فَقَالَ كُلُوا . فَتَنَحَّى بَعْضُ الْقَوْمِ قَالَ إِنِّي صَائِمٌ . فَقَالَ عَمَّارٌ مَنْ صَامَ الْيَوْمَ الَّذِي يُشَكُّ فِيهِ فَقَدْ عَصَى أَبَا الْقَاسِمِ صلى الله عليه وسلم .
Nesai
The Book of Fasting • Hadith 2188