A letter written to Lord Soya in the second year of the Kenji era (1276),
“When this Wisdom and Object are united, one obtains Buddhahood in this Very Body (sokushin jobutsu) . . . That this Inner Realization (naisho) is something that the Hearers and Pratyekabuddhas can understand.” What indeed are these two Dharmas of the Field and the Wisdom (kyochi)? They are just the Five Characters Myoho Renge Kyo. These Five Characters He caused to be formed as the Essence and entrusted (ketsuyo fuzoku) them, summoning forth the Great Beings Who Sprang from the Earth. This they call the Doctrine of Entrusting to Those Converted by the Original Buddha (honge fuzoku). At the same time it appears that the Bodhisattvas Jogyo and the others are to come forth and be born in the first five hundred years of the Latter Dharma and to spread the Five characters that are the two Dharmas of the Field and Wisdom. The Sutra text is clear, it is obvious. Who would dispute this? Although I, Nichiren, am not that person nor am I his Messenger, I have beforehand roughly spread them as a Preface. Already, the Bodhisattva Jogyo having received the water of Wisdom of the Sublime Dharma from the Tathagata Shakya, lets it flow and circulate within the withered up multitudes of beings of the evil era of the Latter Age. This is the principle of Wisdom. Lord Shakya cedes and assigns it to the Bodhisattva Jogyo. At the same time I, Nichiren, being in the country of Japan, spread this doctrine” (STN, V. 2, 1253‑1254).
“On Upbraiding Blasphemy Against the Dharma and Extinguishing sins” (Kashaku hobo metsuzai sho) says
“For more than two thousand two hundred years, the painted and wooden images of the Master of Teachings Lord Shakya were those that the worthy kings and saintly rulers have taken as the Object of Worship. However, it was only the Buddhas of the Lesser Vehicle, the Kegon, the Nehan (Nirvana), the Kangyo, the Manifestation Doctrine (Shakumon) of the Hokekyo, the Fugengyo, of the Great Vehicle, the Buddha of the Dainichikyo of the Shingon, and Shakya and Taho of the Chapter of the Jeweled Stupa. However, Lord Shakya of the Chapter of the Measure of Life is not yet in the temples and monastic residences.” (STN, v. 1, 784).
The Object of Worship for this age is the Eternal Lord Shakya of the Juryo Chapter of the Lotus Sutra. The Dharma is the Daimoku. The ones who are entrusted with that Dharma are the Bodhisattvas Who Sprang from the Earth.
Nichiren identifies these Bodhisattvas in the same work:
“It appears that these Four Bodhisattvas are the people who are the disciples of the Master of Teachings Lord Shakya since kalpas as many as the worlds touched or not by the dust particles of five hundred of tens of trillions of nayutas of assamkheyas of great trichiliocosms (gohyaku jinden go) and who also, from their first arising of the Bodhi Mind, have not adhered to other Buddhas and who have not yet made an appearance in the Two Doctrines [of the Manifestations and the Original]. Tendai says, “He only sees the issuing of vows from the direction below [the Earth]”. He also says, “These are My disciples; they should spread My Dharma” and so on. Myoraku says, “The child spreads the father's Dharma." Tao‑hsien says, “Since the Dharma is the Dharma of the One Who Attained Long Ago, therefore He assigns it to the people of the One Who Attained Long Ago." It is the Five Characters Myo Ho Ren Ge Kyo that He yields to these Four People.” (STN, v. 1, 783‑784).