Nabil-i-Akbar [who was later named by the Guardian as one of the 19 Apostles of Baha’u’llah] was acknowledged as one of the most outstanding men of learning in Persia. His fame had spread throughout the country to such an extent that once, when he spoke incognito to a number of divines in far-off [city of] Kirman, his listeners were lost in admiration of his superb discourse and some were heard to say that the only person in the whole country who could rival such a man in the field of learning and knowledge would be the famous Mulla Muhammad-i-Qa'ini (that is, Nabil-i-Akbar himself).
He embraced the Bábí Faith about the year 1853. Some six years later [about 1859], while in Baghdad, he went to visit Bahá'u'lláh. [this is before Baha’u’llah’s Declaration in the Garden of Ridvan in 1863] There he was warmly received by Him, and was accorded the honour of staying in the outer apartments of His house, normally reserved for the reception of visitors. Mirza Aqa Jan [Baha’u’llah’s amanuensis] was instructed by Bahá'u'lláh to act as host to him. The following is an extract from the spoken chronicle of Nabil-i-Akbar relating the events of those few days that he spent in the house of Bahá'u'lláh:
“One afternoon I was seated in the room talking with Mulla Muhammad-Sadiq-i-Khurasani, known as Muqaddas. He was a learned man of great dignity and stature. As we were talking together, Bahá'u'lláh, Who had just returned from the town, arrived in the outer apartment accompanied by Prince Mulk-Ara whose hand He was holding. Mulla Sadiq, who was the embodiment of dignity and solemnity, immediately rose to his feet and prostrated himself at the feet of Bahá'u'lláh. This action did not please Bahá'u'lláh Who angrily rebuked Mulla Sadiq and ordered him to rise immediately, after which He went out of the room followed by the Prince.
I was amazed and bewildered at such behaviour on the part of Mulla Sadiq as I had never expected such an important person to act in this manner. Having witnessed Bahá'u'lláh's reaction also, I expressed my disapproval of Mulla Sadiq's behaviour and admonished him for it, saying: 'You are a man who occupies an exalted position in the realm of knowledge and learning and, above all else, you had the honour of attaining the presence of the Báb Himself. Your rank is next to the Letters of the Living and you are one of the Witnesses[The Báb nominated certain believers as 'Witnesses' to the Bayan -- the Mother Book of the Bábí Dispensation -- to testify to its validity and authenticity as the Word of God, until the appearance of 'Him Whom God shall make manifest' (i.e. Bahá'u'lláh) when their functions as 'Witnesses' would come to an end.] of the Dispensation of the Báb. It is true that Bahá'u'lláh is an eminent person Who belongs to the nobility and His ancestors have occupied high positions in the government. It is also true that He has suffered persecution and imprisonment as a result of embracing the Cause of God, that all His possessions have been confiscated and that He has finally been exiled to this land. Yet, your behaviour towards Him this afternoon was like that of an unworthy servant towards his glorious Lord.’
Mulla Sadiq refrained from answering me. He was in a state of spiritual intoxication, his face beaming with joy; he merely said to me, 'I beseech God to tear asunder the veil for thee and shower His bounties upon thy person through His abundant grace.'
After this incident, I decided in my heart to investigate and began to observe the person of Bahá'u'lláh and His actions very carefully. The more I observed the less I discovered any sign which could point to His claiming a station. On the contrary, I observed in Him nothing, either in word or deed, except humility, self-effacement, servitude and utter nothingness. As a result, I was led into grievous error, believing that I was in every way superior to Bahá'u'lláh, and preferred my own self to Him.
It was through my vain imagining that in the gatherings of the friends I always used to occupy the seat of honour, assume the function of the speaker and would not give an opportunity to Bahá'u'lláh or anyone else to say anything. One afternoon, Bahá'u'lláh arranged a meeting in His house and a number of friends had gathered, as usual, in the same large room, a room around which, according to the Pen of the Most High, circle in adoration the people of Baha. Again, I occupied the seat of honour. Bahá'u'lláh sat in the midst of the friends and was serving tea with His own hands.
In the course of the meeting, a certain question was asked. Having satisfied myself that no one in the room was capable of tackling the problem, I began to speak. All the friends were attentively listening and were absolutely silent, except Bahá'u'lláh Who occasionally, while agreeing with my exposition, made a few comments on the subject. Gradually He took over and I became silent. His explanations were so profound and the ocean of His utterance surged with such a power that my whole being was overtaken with awe and fear. Spellbound by His words, I was plunged into a state of dazed bewilderment. After a few minutes of listening to His words -- words of unparalleled wonder and majesty -- I became dumbfounded. I could no longer hear His voice. Only by the movement of His lips did I know that He was still speaking. I felt deeply ashamed and troubled that I was occupying the seat of honour in that meeting. I waited impatiently until I saw that His lips were no longer moving when I knew that He had finished talking. Like a helpless bird which is freed from the claws of a mighty falcon I rose to my feet and went out. There three times I hit my head hard against the wall and rebuked myself for my spiritual blindness.”
The eyes of Nabil-i-Akbar were at last opened. He attended another meeting, this time in Kazimayn in the house of a certain Haji Abdu'l-Majid-i-Shirazi. Bahá'u'lláh was present at this meeting. He spoke about the mysteries and origin of creation. Here a new world, full of fresh significances, dawned upon Nabil-i-Akbar who considered every word of Bahá'u'lláh's to be like a priceless gem. All that Nabil-i-Akbar had heard and studied during his life appeared to him to be but the talk of children.
At this point he decided to find out directly from Bahá'u'lláh Himself what His station was and wrote a letter to Him which he begged 'Abdu'l-Bahá to deliver. The next day he received a Tablet in which Bahá'u'lláh alluded to His lofty station. This was the end of Nabil-i-Akbar's search for truth, for he wrote a second letter to Bahá'u'lláh, this time humbly acknowledging Him as the Supreme Manifestation of God and begging Him to guide his steps in His service. Bahá'u'lláh instructed him to return to Persia and teach the Cause of God there.
Nabil-i-Akbar dedicated his whole life to the service of the Cause, suffering much persecution from the enemies of the Faith. He rose to such heights of service and dedication that few among the Apostles of Bahá'u'lláh have been able to rival his attainments.
He died in 1892 soon after the ascension of Bahá'u'lláh and was buried in the city of Bukhara. 'Abdu'l-Bahá asked that a delegation of nine believers visit his grave on His behalf and there chant a Tablet of visitation which He had written especially for him. A few years later He instructed the nephew of Nabil-i-Akbar to transfer his remains from Bukhara to Ishqabad -- a move which proved providential as the graveyard was demolished soon after by the authorities. (Adib Taherzadeh, ‘The Revelation of Baha’u’llah, vol. 1, pp. 92-94)