On the day of Ashura, Shi‘a Muslims all over the world commemorate the martyrdom of Imam Husayn ibn Ali, the grandson of Prophet Muhammad, at the Battle of Karbala, in protest against the oppressive ruler Yazid who ordered the massacre of Imam Husayn and his family members and companions given their refusal to accept Yazid’s allegiance. In mourning on this day, the tradition of matam, or beating one’s chest as a sign of grief for the Imam, became common. Moreover, tatbir, a more serious form of displaying one’s sorrow, was also practiced, and then afterwards banned in the Islamic Republic of Iran. This article provides an analysis as to why the ban occurred using the Qur’an, hadiths, and consensus of Shi‘a scholars to verify the forbiddance of this act.