Is it permissible to observe Sawm (Fast) on the day of `Ashura' (the 10th day of the month of Al-Muharam) alone?
It is permissible to observe Sawm on the day of `Ashura' only but it is better to observe Sawm one day before or after it. This is the authentic Sunnah (commendable act) reported from the Prophet (peace be upon him) as he said:
If I live till next year I will fast the ninth
Ibn `Abbas (may Allah be pleased with them) said, 'That is to say, along with the tenth day.'May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.