Sayyiduna Muhammad bin Saifi Ansari (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings be upon him) came to us on the Day of Ashura and asked: Have you people fasted today? Some said: Yes, and some said: No. He (peace and blessings be upon him) said: In any case, complete the fast for the rest of the day. He (peace and blessings be upon him) also instructed them to inform the people of ‘Aroud so that they too may complete the fast of this day.