Question: It is known that the Day of `Arafah (9th of Thul-Hijjah) coincided with a Friday. We observed Sawm (Fast) on that day based on the Hadeeth in which the Prophet (peace be upon him) said: Observing Sawm on the Day of `Arafah expiates for the previous year and the coming one. (Related by Muslim) The Imaam (the one who leads congregational Prayer) of our Masjid (mosque) told us that it is not permissible to observe Sawm on a Friday unless one observes Sawm a day before or after it. Therefore, most of us broke our Sawm, while the others continued their Sawm even though they were confused.
Please note that our Sawm was in reverence for the Day of `Arafah, seeking its reward, and not out of preference for Friday. Please give us a Fatwaa (legal opinion issued by a qualified Muslim scholar), may Allaah benefit you. Who is right: the Imaam of our Masjid and those who broke their Sawm on that day, or those who continued their Sawm? What should we do if the Day of `Arafah or `Ashooraa’ (10th of Muharram) coincides with a Friday?
Answer: It was authentically reported that the Prophet (peace be upon him) forbade singling out Friday for observing Sawm and he ordered that one is to observe Sawm one day before or after it… read more here.