Sila bin Zufar said: We were with Sayyiduna Ammar bin Yasir (may Allah be pleased with him) when he brought a roasted goat and said: Eat. A man withdrew and said: I am fasting. Sayyiduna Ammar bin Yasir (may Allah be pleased with him) said: Whoever fasts on the day of doubt has disobeyed Abul Qasim (peace and blessings be upon him).