Abd al-Aziz ibn Baz
According to Salafi Sunni scholars such as Ibn Taymiyyah and Abd al-Aziz ibn Baz, the celebration of Ashura is itself a blatant and primary example of the propensity of the Shia to indulge in "Bid‘ah" (religious innovation). They argue that the annual mourning occasion for Husayn (or any other individual) was never instituted or practiced by Muhammad — not even for his closest family members — and hence has no validity in Islam. Likewise, Ibn Rajab in his "Kitab al-Iata'if" argued against Ashura: "Neither God ..., nor His Messenger ... have ordered that days on which prophets met with calamities and the day of their death be instituted as a day of mourning. How much more is this true for a person lesser than they?"