He was "outed" as a Bahá'í when he arose to defend the community in the aftermath of the assassination of the Shah in April of 1896. Until official word came from Iran through the Consulate that the Bahá’ís were not involved, a number of Shi‘at Iranian expatriates were calling for a retaliatory massacre of the Bahá’ís in Egypt. It was during this period that at a gathering in the Iranian Consulate, Mírzá Abú’l-Fadl openly declared himself to be a Bahá’í.

Mírzá Abú’l-Fadl had by this time established contacts with the Egyptian press. When news reports containing charges that the Bábís were behind the Shah’s assassination began to circulate, Ya‘qub Sarruf and Farís Nimr asked Mírzá Abú’l-Fadl for an article on the Bábí and Bahá’í movements for their secular-minded journal, al-Muqtataf. Mírzá Abú’l-Fadl complied, and as such brought the history and teachings of the Faith to the attention of intellectuals throughout the Arab world. [Memories of the Báb, Bahá'u'lláh and `Abdu'l-Bahá By Mírzá Habíbu'lláh Afnán p58-59; 65]

During this period, a number of early treatises were published in Cairo, including: an Arabic polemical history of the Bábís by Mírzá Muhammad-Mihdí Khán, the Za’ímu’d-Dawlih (The Key to the Gate of Gates, was printed in Cairo in 1903 (Supposedly this was a dispassionate account of the Bábís and Bahá’ís, but in fact a distortion of truth, and in effect, as attested by ‘Abdu’l-Bahá, intended to arouse passions against the Bahá’ís.); numerous titles in Persian, including collection of Tablets, prayers and poetries of Bahá’u’lláh, His Epistle to the Son of the Wolf, The Seven Valleys, The Four Valleys;. He published the first series of Bahá'í books in Egypt, including the first three-volume compilation of `Abdu'l-Bahá's Tablets, which the Master entitled Makatib-i-`Abdu'l- Bahá. Mírzá Abú’l-Fadl’s Kitáb Fará’id, Dawra’l-Bahiyyih, and Hujaju’l-Bahiyyih; and Hájí Mírzá Haydar-‘Alí’s Dalá’ilu’l-‘Irfán. Publications in Arabic included Bahá’u’lláh’s Ishráqát, Tajallíát, Tarázát, and Kalamát. Myron H. Phelps completed his work, Life and Teachings of Abbas Effendi, when in Cairo in March 1903. ['Abdu'l-Bahá in Egypt: A Compilation of Eyewitnessess by Ahang Rabbani p 4-5]

See as well 'Abdu'l-Baha's First Thousand-Verse Tablet: History and Provisional Translation by Ahang Rabbani and Khazeh Fananapazir pg 107-108.