Sayyiduna Salamah bin Akwa’ (may Allah be pleased with him) narrated that the Prophet Muhammad (peace and blessings be upon him) sent a man on the day of ‘Ashura to announce that whoever has eaten should complete (the fast) for the rest of the day (i.e., remain in the state of fasting until sunset), or (he said) should fast, and whoever has not eaten should (begin to) fast and not eat.