circa 1850: Nabil, the author of Dawn-Breakers, took ‘Abdu’l-Baha to school one day

One day Mírzá Ahmad conducted me [Nabil, he was then about 19 years old] to the house of Bahá’u’lláh, whose wife, the Varaqatu’l-’Ulya, [the Most Exalted Leaf] the mother of the Most Great Branch, had already healed my eyes with an ointment which she herself had prepared and sent to me by…Mírzá Ahmad.

The first one I met in that house was that same beloved Son of hers, who was then a child of six. He smiled His welcome to me as He was standing at the door of the room which Bahá’u’lláh occupied. I passed that door, and was ushered into the presence of Mírzá Yahyá, [Baha’u’llah’s half-brother] utterly unaware of the station of the Occupant [Baha’u’llah] of the room I had left behind me….

On another occasion, when I visited that same house, I on the point of entering the room that Mírzá Yahyá occupied, when Áqáy-i-Kalím, [Baha’u’llah’s faithful brother] whom I had previously met, approached and requested me, since Isfandíyár, their servant, had gone to market and had not yet returned, to conduct “Áqá” [‘Abdu’l-Baha] to the Madrisiy-i-Mírzá-Sálih [school] in his stead and then return to this place. I gladly consented, and as I was preparing to leave, I saw the Most Great Branch, a child of exquisite beauty, wearing the kuláh [hat]  and cloaked in the jubbiy-i-hizari’í, [A kind of overcoat] emerge from the room which His Father occupied, and descend the steps leading to the gate of the house. I advanced and stretched forth my arms to carry Him. “We shall walk together,” He said, as He took hold of my hand and led me out of the house.

We chatted together as we walked hand in hand in the direction of the madrisih [school] known in those days by the name of Pa-Minar. As we reached His classroom, He turned to me and said: “Come again this afternoon and take me back to my home, for Isfandíyár is unable to fetch me. My Father will need him to-day.” I gladly acquiesced, and returned immediately to the house of Bahá’u’lláh…

I… returned to the madrisih in time to conduct the Most Great Branch to His home. 

- Nabil  (‘The Dawn-Breakers’, translated and edited by Shoghi Effendi)

Quddús’ amazing ability to pen copious writings – their recital and tributes by Mulla Husayn provided daily spiritual food at Fort Tabarsi

We know from the Baha’i Writings that Quddus, in addition to being the last Letter of the Living and the chosen companion of the Báb during His pilgrimage to Mecca, has a high station. The Guardian elucidates on it in ‘God Passes By’:

“Quddús, immortalized by Him [the Báb] as Ismu'llahi'l-Akhir (the Last Name of God); on whom Bahá'u'lláh's Tablet of Kullu't-Ta'am later conferred the sublime appellation of Nuqtiy-i-Ukhra (the Last Point); whom He elevated, in another Tablet, to a rank second to none except that of the Herald of His Revelation; whom He identifies, in still another Tablet, with one of the ‘Messengers charged with imposture’ mentioned in the Qur'án; whom the Persian Bayan extolled as that fellow-pilgrim round whom mirrors to the number of eight Vahids revolve; on whose ‘detachment and the sincerity of whose devotion to God's will God prideth Himself amidst the Concourse on high;’ whom 'Abdu'l-Bahá designated as the ‘Moon of Guidance;’ and whose appearance the Revelation of St. John the Divine anticipated as one of the two ‘Witnesses’ into whom, ere the ‘second woe is past,’ the ‘spirit of life from God’ must enter” (Shoghi Effendi, 'God Passes By')

Here is an example of Qúddus’ amazing keenness of understanding concerning the manifold meanings of the Word of God: 

Following the conference of Badasht, Quddús was en route to his home town when he fell into the hands of his opponents and placed under house arrest.

Nabil, the great Baha’i chronicler, explains that while Quddus was in confinement in the home of a leading clergy of the town of Sari, Mírzá Muhammad-Taqí, the latter asked Quddús “to write a commentary on the Súrih of Ikhlas, better known as the Súrih of Qul Huva’lláhu’l-Ahad” (Nabil, ‘The Dawn-Breakers’, translated and edited by Shoghi Effendi).