What some Muslim groups do on ‘Ashoora’ by beating their chests, slapping their cheeks, striking their shoulders with chains and cutting their heads with swords to let the blood flow are all innovations that have no basis in Islam. These things are evils that were forbidden by the Prophet (peace and blessings of Allaah be upon him), who did not prescribe for his ummah to do any of these things or anything similar to them to mark the death of a leader or the loss of a martyr, no matter what his status.
During his lifetime (peace and blessings of Allaah be upon him) a number of senior Sahaabah were martyred and he mourned their loss, such as Hamzah ibn ‘Abd al-Muttalib (ra), Zayd ibn Haarithah (ra), Ja’far ibn Abi Taalib (ra) and ‘Abd-Allaah ibn Rawaahah (ra), but he did not do any of the things that these people do. If it was good, he (peace and blessings of Allaah be upon him) would have done it before us.
Al-Bukhaari (1294) and Muslim (103) narrated that ‘Abd-Allaah ibn Mas’ood (may Allaah be pleased with him) said: The Prophet (peace and blessings of Allaah be upon him) said: “He is not one of us who strikes his cheeks, rends his garment, or cries with the cry of the Jaahiliyyah.” -