He [Nabil] states in his narration that he met the maternal
uncle of the Bab, Haji Mirza Siyyid Ali who had visited his nephew in the
Castle of Chihriq and had recently returned to Tihran. He started writing his
narrative in 1305 A.H. four years before the passing of Bahá'u'lláh. It took
him about a year and half to write it. His chief informants were Mirza Ahmad
the amanuensis of the Bab and Mirza Musa the brother of Bahá'u'lláh. Parts of
his narrative were read in the presence of Bahá'u'lláh and approved by Him.
'Abdu'l-Bahá also went over sections of his narrative....
- Shoghi Effendi (From
a letter dated 30 November 1930, written on behalf of Shoghi Effendi; printed
in ‘The Unfolding Destiny of the British Baha'i Community’)