Sila bin Zufar narrates: We were present with Sayyiduna Ammar bin Yasir (may Allah be pleased with him) when a roasted goat was brought. He said: Eat the food. One person withdrew and said: I am fasting. Sayyiduna Ammar bin Yasir (may Allah be pleased with him) said: Whoever fasts on a day about which he is doubtful, then he has disobeyed Sayyiduna Abul Qasim (the Prophet Muhammad) (peace be upon him).
Hadith Referenceصحیح ابن حبان / كتاب الصوم / 3595
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - مضى (3577). تنبيه!! رقم (3577) = (3585) من «طبعة المؤسسة». - مدخل بيانات الشاملة -.فضيلة الشيخ العلّامة شُعيب الأرناؤوطصحيح