On the publication of Dafi‘ul Bala’ Wa Mi‘yaro Ahlil-Istifa’, wherein Hazrat Mirza Ghulam Ahmad (as) declared that the plague was another heavenly sign from God in his favour and that Qadian would remain protected against this calamity and challenged the leaders of all other faiths to make a similar prophecy about the city of their importance. 

Pir Mehar ‘Ali Shah, published a number of false reports asserting that deaths had occurred on account of the plague in Qadian and raised silly objections to the prophecy about the safety of Qadian.

Then Hazrat Mirza Ghulam Ahmad (as) undertook a refutation of such allegations. The Promised Messiah (as) wrote Nuzulul Masih with the idea of presenting a complete gist of his entire literature, which could mirror the salient points repeatedly expounded by him. He then recalled eleven clear Divine signs, which decisively confirmed his Mission. He mentioned a number of revelations including 123 prophecies that were perfectly and clearly fulfilled as foretold and claimed a large number of eyewitnesses were still alive at that time.

Hazrat Mirza Ghulam Ahmad (as) also elucidated the true position of Hazrat Imam Hussain, who was claimed by the followers of the Shia faith to be a saviour, even of the Holy Prophet (sa).

In the meantime, the devious Pir Mehar ‘Ali Shah did another mischief. Instead of writing a comparable commentary on surah al-Fatihah as asked by Hazrat Mirza Ghulam Ahmad (as) in his book Ijaz-ul-Masih, he wrote a book, Saif-e-Chishtiya’i, making fun of some of the Arabic phrases used in Ijaz-ul-Masih and alleged that some of the material is plagiarized and further alleged that the Revelations of Hazrat Mirza Ghulam Ahmad (as) are no more than confused dreams.

Explaining the use of relevant quotes from other authorities, Hazrat Mirza Ghulam Ahmad (as) stated that these quotes do not constitute plagiarism, otherwise, everyone will be exposed to this charge. It so happened that Mian Shahabuddin and Maulavi Karam Din in their correspondence with Hazrat Mirza Ghulam Ahmad (as) mentioned that most of the material appearing in Saif-e-Chishtiya’i written by Pir Mehar ‘Ali Shah is copied word by word from the notes of Maulavi Muhammad Hasan Faidi and these notes were written by him on the margins of the books Ijaz-ul-Masih and Shamse Bazighah and these books carrying marginal notes were bought. This is how the devious Pir was exposed who made the allegations that the Promised Messiah (as) had plagiarized whereas the same charge recoiled on him.

Hazrat Mirza Ghulam Ahmad (as) also replied to the criticism that Pir Mehar ‘Ali Shah made in his book, Saif-e-Chishtiya’i about the merit of the Ijaz-ul-Masih. THe also established that the revelations made to him were revelations of a high order.

The Pir also made an allegation that the Hazrat Mirza Ghulam Ahmad (as) had been plagiarizing from Maqamat-e-Hariri but what actually transpired was that Pir Mehar ‘Ali Shah had himself plagiarized from the notes of Maulavi Muhammad Hasan Faidi which the Maulavi had written marginally on the Ijaz-ul-Masih and Shamse Bazighah by Hazrat Maulavi Muhammad Ahsan Amrohi. This information was given by Mian Shahabuddin and Maulavi Karam Din in their letters to the Hazrat Mirza Ghulam Ahmad (as). This whole correspondence has also been published in this book.

(Taken from An Introduction to the hidden Treasures of Islam)