The Great Concentration and Insight states:

“What does it mean to listen to a perfect teaching? It means that one’s ephemeral body would instantly be transformed into that of the everlasting Dharma Body, one’s evil passions into unsurpassed wisdom, and one’s evil karma into emancipation. As it is observable, there are three names to this, but only one thing to which it refers. In short, three aspects have been connected with one phenomenon. In fact, since these three concepts all concern one entity, there should be no differences among them. Should one approach the epitome of the Dharma Body, then one also nears the utmost of wisdom and emancipation. Should one’s wisdom be pure and just, then it follows that one’s Dharma Body and emancipation would also be thus. Should one’s emancipation be free and flowing, then it can be assumed that one’s Dharma Body and wisdom would also be thus. In this way, parallels not only exist between the three bodies and the three evils, but in all phenomena. For this reason, all phenomena are intertwined with notions of Buddhist dharma, such that nothing is missing. This manner of viewing things is what is meant by ‘listening to a perfect teaching.’ ”

This interpretation represents a guide to the opening and merging of sōtai seed.

Shimon Butsujō-gi, Listening to the Once Buddha Vehicle Teachings for the First Time, Writings of Nichiren Shōnin, Doctrine 2, Page 246-247

[I]n Japan, too, the king of devils in the Sixth Heaven mobilizes the troops of ten devils, fighting over this land against practicers of the Lotus Sūtra in the sea of life and death. I, Nichiren, have accompanied the army of those aggressively spreading the Lotus Sūtra for twenty years, without ever entertaining any thoughts of retreat. However, some of my disciples and followers who are weak-willed have mostly given up the faith in the Lotus Sūtra due to the constant persecutions; even among the remaining faithful there are some who are already showing signs of losing interest. Nevertheless, it is commendable for you to have kept your faith in the Lotus Sūtra, though you do not know much about Buddhism. What is more, you even sent your servant all the way to Sado Island to help me. Śākyamuni Buddha and the Buddha of Many Treasures, and many other Buddhas in manifestation coming from all over the universe will be sure to applaud such merits of yours.

Ben-dono Ama Gozen Gosho, A Letter to My Lady, the Nun of Ben-dono, Writings of Nichiren Shōnin, Biography and Disciples, Volume 5, Pages 156-157

Regarding further the background of the ullambana, Maudgalyāyana was an unenlightened man who was unaware of his mother’s suffering in the realm of hungry spirits. As a child he received a non-Buddhist education in Brahmanism, mastering all the non-Buddhist scriptures such as the four Vedas and eighteen great sūtras, but he was still unable to see where his mother had gone after her death. Later, at the age of 13 Maudgalyāyana, together with Śāriputra, visited Śākyamuni Buddha and became His disciple. He became a sage of the initial rank by eliminating delusions of views, rose to the rank of arhat by overcoming delusions of thought, and gained the three or six kinds of supernatural powers.

With his heavenly eyes wide open, Maudgalyāyana could see everything throughout the triple thousand worlds as though they were all reflected in a spotless mirror. He was able to see everywhere in the great earth and in the three evil realms. It was as if he were looking at the fish below the water through the ice shining in the morning sun. It was then he saw his own mother in the realm of hungry spirits.

Without anything to eat or drink, his mother was emaciated, and her skin looked like a pheasant whose feathers were all plucked, and her bones were worn away to such an extent that they looked like lines of round stones. Her head without hair looked like a ball, her neck as thin as a thread, and her stomach swollen as large as the ocean. Her appearance, as she begged by opening her mouth wide and pressing her palms together, resembled a leech trying to catch the scent of human beings. How heartbreaking it was for Maudgalyāyana to see his own mother, suffering from hunger and wanting to cry at the sight of her own son in her previous life! It must have been sadness beyond description. …

Venerable Maudgalyāyana felt so sorry for his mother that he made use of his supernatural powers to send a meal to her. His mother gladly grabbed the meal with her right hand and put it into her mouth while covering it with the left hand. At this moment the meal somehow changed into fire, bursting into flames, as if wicks were put together to build a fire, causing the mother to get burned all over. Shocked at seeing this, Maudgalyāyana hurriedly used his supernatural powers again to pour plenty of water. The water, however, somehow changed to firewood, causing more burns to his mother. It was a dreadful scene!

Realizing that his own supernatural powers were not enough to save his own mother, Maudgalyāyana hurriedly went to see the Buddha and cried, “I was born in a non-Buddhist family, but became a disciple of the Buddha and ascended to the rank of arhatship, won freedom from the chain of life and death in the triple world, and gained the three or six supernatural powers of arhatship. However, when I tried to save my mother from the great suffering in the realm of hungry spirits, I only intensified her suffering. I am grief-stricken.” The Buddha replied to Maudgalyāyana, “Your mother’s sin is too serious for you alone to save her. No matter how many persons there are, the powers of such as heavenly beings, terrestrial gods, demons, non-Buddhists, Taoist priests, the Four Heavenly Kings, Indra, and the King of the Brahma Heaven cannot save her. You can only save your mother from suffering by gathering holy priests in all the worlds throughout the universe on the 15th of the 7th month, treat them with a feast.” As Maudgalyāyana held a feast according to the instructions of the Buddha, his mother was able to escape the kalpa (aeon) of suffering in the realm of hungry spirits. So, it is preached in the Ullambana Sūtra.

Stemming from this, people in the Latter Age of Degeneration after the passing of the Buddha hold the ullambana service every year on the 15th of the 7th month. Today this is a common practice held as an annual event.

Urabon Gosho, On theUllambana Service, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 172-173

“Evil passions” can be categorized into three delusions: delusions arising from incorrect views and thoughts, delusions as numerous as particles of dust and delusions which hinder the knowledge of the ultimate reality. “Bad actions” refer to such serious sins as the five rebellious sins, the ten evil acts and the four major sins. Dharma Body stands for the Buddha with the Dharma Body, unsurpassed wisdom stands for the Buddha with the Reward Body, and emancipation refers to the Buddha with the Accommodative Body. From an indefinite past, we have been connected with the three paths: evil passions, karma and suffering. Fortunately, because of our association with the Lotus Sūtra, we can be assured that the illusions of the three paths instantly convert to the three merits of Dharma Body, unsurpassed wisdom, and emancipation.

Shimon Butsujō-gi, Listening to the Once Buddha Vehicle Teachings for the First Time, Writings of Nichiren Shōnin, Doctrine 2, Page 247

[There] once was an ordinary man who strictly observed the precept against telling lies. Although his eyes were gouged out, his skin stripped, his flesh cut off, his blood sucked up, his bones broken, his children killed, and his wife attacked, he refused to lie even once for innumerable kalpa (aeons), and thereby attained Buddhahood. As the Buddha, he then preached the Expedients chapter in the Lotus Sūtra: “There is none who will not become a Buddha.” Namely, he has preached that anyone who said “Namu Myōhō Renge Kyō” even once will not fail to become a Buddha. Even if Śākyamuni Buddha alone said this, there should be absolutely no doubt about its veracity. How could the Buddha utter a false statement before the assembly of various Buddhas from all the worlds in the universe? Besides, Śākyamuni Buddha as well as all the Buddhas from the worlds throughout the universe at the same time extended their long tongues to the Mahābrahman Heaven to prove its truthfulness.

Nanjō-dono Gohenji, Reply to Lord Nanjō, Writings of Nichiren Shōnin, Followers II, Volume 7, Page 41-42

Though the meaning of five letters of myō, hō, ren, ge, and kyō is interpreted differently depending on the commentators and teachers, they are all based on provisional sūtras, so that none of them is correct. However, Bodhisattva Nāgārjuna writes in his Great Wisdom Discourse, “The wonder of the Lotus Sūtra is like a great pharmacist making medicine out of poison.” I believe this interpretation shows that he grasped the meaning of the character myō. The poison in this case means the truth of suffering in this life and the truth regarding the cause of suffering (evil passions and karma in previous existences). Thus, the cause and effect of life and death is the poison of poison. The Lotus Sūtra preaches that the illusions of life and death at once become Nirvana, and the illusions of evil passions are equal to enlightenment. This means that the poison was changed into excellent medicine due to the ultimate teaching of myō. Excellent medicine refers to the one made of poison.

Ōta-dono Nyōbō Gohenji, A Response to the Wife of Lord Ōta, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 167

QUESTION: The Nirvana Sūtra states that the number of people who practice the sūtra is as little as soil on a fingernail, while you hold that the number of those who practice the Lotus Sūtra is as rare as the soil on a fingernail. What is the difference?

ANSWER: The Nirvana Sūtra preaches, “In the Lotus Sūtra eight thousand śrāvakas were guaranteed to obtain Buddhahood in the future by the Buddha. This means that the Lotus Sūtra finished reaping the great harvest in autumn to store for winter, leaving only the gleaning to the Nirvana Sūtra.” Grand Master Miao-lê says that the Great Sūtra considers the Lotus Sūtra to be supreme. The Great Sūtra stands for the Nirvana Sūtra, so the Nirvana Sūtra regards the Lotus Sūtra as the supreme teaching. However, the people of the Nirvana School say that the Nirvana Sūtra is superior to the Lotus Sūtra. This is like calling a master a follower, and low-ranking warriors high-ranking warriors. Reading the Nirvana Sūtra means reading the Lotus Sūtra. A sage is content even when he himself is despised so long as his king is respected. Likewise, the Nirvana Sūtra dislikes those who despise the Lotus Sūtra and who admire the Nirvana Sūtra.

Hōon-jō, Essay on Gratitude, Writings of Nichiren Shōnin, Doctrine 3, Pages 35.

Now, as far as my theology goes, I would like you to think that what I have expressed before being banished to Sado Island can be equated with the forty or so years in which Śākyamuni had taught before revealing the Lotus Sūtra (that is, the truth and true aims of the Buddha were not directly divulged in those years). If the ruler of this country desires to govern the people under a proper political principle, then there will always be an opportunity for me to debate with the priests of the Shingon Sect. I shall expound my precious teaching for the first time then. Even if I had discussed this only within the circle of my disciples, some of it would bound to have leaked out making it difficult to conduct a discussion (as a result of their scheming). Such is why I have kept quiet about this to all of you. However, ever since the night of the twelfth of the ninth month in the eighth year of the Bun’ei Period (1271), when I was about to be beheaded at Tatsunokuchi (on the outskirts of Kamakura), I have come to think that it was unwise of me to have kept the truth from some of you who have stuck with me. There is a teaching I have disseminated quietly from the island of Sado (where I had been banished) to my disciples.

This is a teaching which great commentators in India and great masters in China and Japan who have come after the Buddha, such as Kāśyapa, Ānanda, Nāgārjuna, Vasubandhu, T’ien-t’ai, Miao-lê, Dengyō and Gishin, knew to be true in their hearts but never imparted. This is because the Buddha had strictly warned that, “this important teaching should not be passed on in the thousand years of the Age of the True Dharma and thousand years of the Age of the Semblance Dharma before entering the Latter Age of Degeneration.” Nichiren is not a direct emissary of the Buddha; however, as long as I have come to be in this Latter Age of Degeneration and have, quite beyond expectations, attained this doctrine, I would like to transmit it in the capacity of a herald, until Bodhisattva Superior Practice, a messenger of the Buddha, appears. Once this teaching is exposed, the teachings spread by the elders during the Ages of the True Dharma and Semblance Dharma would pale in comparison, just as the stars are obscured by the rising sun, or as if we see a dull performance after a skillful one. It is written in the sūtras that when the Latter Age of Degeneration dawns, such things as the spiritual power of Buddhist sculptures and priests of the temples built in the Ages of the True and Semblance Dharmas would be effaced; and its only legacy would be the dissemination of this great teaching throughout the world (Jambudvīpa). All of you should feel grateful that you are endowed with the opportunity to have come across such a wonderful teaching.

Misawa-shō, A Letter to Lord Misawa of Suruga, Writings of Nichiren Shōnin, Doctrine 2, Page 241-242

Note: This letter represents a vital piece of evidence provided by Nichiren himself upon which many scholars rely in supporting the fact that there exists a difference in Nichiren’s revelation of doctrines and intensity of teaching before and after his Sado exile.

I am to leave for Sado Province in exile on the 7th of this month. As all of you who are put in prison due to your faith in the Lotus Sūtra actually read through one book of the Lotus Sūtra physically and spiritually, you not only reap the merits yourself, but extend the merits to the souls of your parents, brothers, and sisters as well.

Gonin Tsuchirō Gosho, A Letter to Five Disciples in a Dungeon, Writings of Nichiren Shōnin, Biography and Desciples, Volume 5, Page 153