The Fatwa of Kufr was first published by Ahmad Raza Khan in 1902 through the work al-mu‘tamad al-mustanad. The takfir got more famous under the name Hussam al-Haramayn in 1906 after his hajj, in which he tried to convince the Arab scholars for the validity of his mass takfir. He published the book once back in India.
The reply of the Deobandi scholars came immediately in 1907 through the work al-muhannad ‘ala al-mufannad written by Mawlana Khalil Ahmad Saharanpuri.
Another work was written by Mawlana Husayn Ahmad Madani called al-Shihab al-Thaqib. Ahmad Raza Khan refers to this work in his book Khalis al-I’tiqad. Mawlana Chandpuri, the khalifa of Mawlana Thanwi, wrote several books against him and challenged him for a debate. Ahmad Raza Khan in his Fatawa mentions Mawlana Chandpuri and his unwillingness to debate a khalifa instead of Mawlana Thanwi, who appointed his khalifa on his behalf in order to debate the issue at hand.
Ahmad Raza died in in 1921 so he had more than 10 years to ponder over his takfiri fatwa, but to no avail. Ahmad Raza Khan knew very well the arguments of his opponents and knew about the fabricated fatwa ascribed to Ml. Gangohi.
Despite all of this, the Barelwis still call their leader Ahmad Raza “hesitant and cautious” in takfir. How funny!