Chapter 13, “Encouragement to Uphold the Sutra,” also teaches entrusting to bodhisattvas the mission of disseminating the Dharma in the evil age, and especially emphasizes the practice of martyrdom by bodhisattvas who are so entrusted. The chapter closes with bodhisattvas vowing to disseminate the Dharma despite intolerable suffering. Nichiren, who suffered many hardships in his life, and his followers, who were also believers in the Lotus Sutra, were encouraged and supported by this exaltation of the spirit of martyrdom, and by the teaching of “the apostles of the Tathagata” found in chapter 10. These teachings also gave them a sense of being among the religious elite and helped create strong bonds of communal friendship. Some contemporary scholars comment that this bodhisattva sense of being an apostle or a martyr is unique within Buddhism.

Because the Lotus Sutra generates such a bodhisattva spirit, some suspect that a distinct group produced it. Even if such a group did exist, since there is no concrete evidence for it, the idea that it existed is no more than conjecture. Rather, the bodhisattva spirit that the Lotus Sutra emphasizes was a radical version of the idea of the bodhisattva way that is generally found in Mahayana Buddhism. So it seems that we need not treat the Lotus Sutra as a special case.

Chapter 12 tells about the future becoming a buddha of Devadatta, the extremely evil one who rebelled against Shakyamuni, and the sudden awakening of an eight-year-old dragon girl. This chapter has been revered since ancient times as an expression of the awakening of evil people and women. While the esoteric Shingon school often uses the term “becoming a buddha in one’s present” it was first used when Zhanran, the sixth patriarch of the Chinese Tiantai school, interpreted chapter 12. The chapter may have been inserted into the Lotus Sutra later and does not form a natural part of the narrative line of the sutra as a whole. Yet, for the reason mentioned above, it is still revered and recited.
Yoshiro Tamura, "Introduction to the Lotus Sutra", p77

[In chapter 11] there is the sudden appearance of the Treasure Stupa, the two buddhas sitting side by side, the gathering together of the buddhas who are embodiments or representatives of Shakyamuni, the united buddha-land, the purification of the Sahā world, and so on. These things were traditionally understood to imply that Shakyamuni Buddha is the Everlasting Original Buddha, and were taken to herald chapter 16, “The Life of the Tathagata.” But chapter 11 also teaches the propagation of bodhisattva practice, which is its ultimate purpose. We can see this in the following:

Who is able to teach the Wonderful Dharma Flower Sutra everywhere throughout this world? Now indeed is the time. Before long the Tathagata will enter nirvana. So that it will last forever, the Buddha wants to entrust this Wonderful Dharma Flower Sutra to someone.

Thus, it encourages actual bodhisattva practice in this world during the latter days and teaches the entrusting of the Dharma to such bodhisattvas.

It is implicit in chapter 11 that Shakyamuni both exists eternally and unifies the bodies of the various buddhas. The Treasure Stupa hangs in the air, with the two buddhas—Abundant Treasures and Shakyamuni— sitting in it side by side. Shakyamuni going to the seat in the Stupa in the air represents the infinite spatial extension of his world. Since Abundant Treasures Buddha is a previous form of Shakyamuni Buddha, their sitting side by side represents the infinite temporal extension of Shakyamuni’s existence. The various buddhas of the ten directions are embodiments of Shakyamuni, which indicates that the true body of Shakyamuni is manifested everywhere. The return to Shakyamuni of all of these embodiments of him as he enters the Stupa indicates that the worlds of the ten directions are unified into one buddha-land. This, too, is intended to reveal that Shakyamuni Buddha is a unifying Buddha.

In chapter 11, a jeweled Stupa rises up out of the ground and hangs in the air. Shakyamuni Buddha shifts his seat from Mt. Gṛdhrakūṭa to the jeweled Stupa in the air. Thus the scene changes from the meeting place on Mt. Gṛdhrakūṭa to the meeting place in the air. After chapter 22, the setting returns to Mt. Gṛdhrakūṭa. This has been called the “three meetings in two settings.”

The especially notable things in chapter 11 include the rising up out of the ground of a jeweled stupa, the two buddhas sitting side-by-side, the gathering together of Shakyamuni Buddha’s embodiment or representative buddhas, and the one universal buddha-land. … This chapter also teaches and explains the so-called “six difficult and nine easy practices” concerning the proclamation of the Lotus Sutra. Further, the verses at the end of the chapter, from “This sutra is so difficult to embrace . . .” up to the last phrase, . . . should receive offerings from all human and heavenly beings,” are known as “the phrases of difficulty in embracing the sutra,” or the “jeweled Stupa verses.” Even now people continue to recite them frequently.

In chapter 11, “The Sight of the Treasure Stupa,” a jeweled Stupa in which Abundant Treasures (Prabhūtaratna) Tathagata sits floats in midair. Shakyamuni Buddha goes from the ground to the Stupa in the air and sits beside Abundant Treasures Buddha. With that, the buddhas who are embodiments or representatives of Shakyamuni Buddha come from various directions to be united with him, while at the same time, various worlds are united into a single buddha-land. Abundant Treasures is a buddha who appeared prior to Shakyamuni. One can understand that the two of them sitting side-by-side symbolizes that Shakyamuni has been a buddha from the very remote past—that is, it suggests the universality of Shakyamuni Buddha. The gathering together of the buddhas embodying Shakyamuni from throughout the universe and the common buddha-land express the idea that Shakyamuni Buddha is a unifying buddha.

In this sense, chapter 11 should be taken as a kind of prelude to chapter 16, “Ihe Lifetime of the Tathagata.” As in chapter 16, this chapter also emphasizes bodhisattva practice, advocates actual bodhisattva practice in the heart of this Sahā world during the last days, and teaches entrusting the Dharma to bodhisattvas. Thus, we ought to reexamine ideas such as the jeweled Stupa rising up, the gathering together of buddha embodiments, and a common buddha-land from the perspective of promoting bodhisattva practice.

Nichiren was especially attracted to the term “apostle” or “emissary” of the Tathagata, which appears [in chapter 10]. Influenced by this term, Nichiren used the phrase “follower of the Lotus Sutra.” The Lotus Sutra says, in connection to the phrase “emissaries of the Tathagata,” that those who devote themselves to embodying the truth in this world even a little are people who have been sent from the pure world of the Buddha to be born in this world because they have compassion for people. This suggests a meaning or purpose for being born in this world. Nichiren was able to gain courage and meaning for living from this kind of phrase, despite having to bear much suffering.

Chapter 10 teaches the unifying and ultimate cosmic truth, i.e., the Wonderful Dharma of One Vehicle. What had previously been revealed should now be put into practice in this actual world, and thus made concrete. This idea emphasizes the bodhisattva way. Bodhisattvas, who have thus far played only modest roles in the sutra, now come to the fore as the main actors. …

The so-called “three principles for spreading the sutra” and the parable of the thirsty man have traditionally been highly valued and given prominence in the tenth chapter. The three principles are three tracks for practicing the truth in the real world: compassion, patience, and the ability to see the emptiness of all things. These three are represented in chapter 10 by the room, the robe, and the seat of the Tathagata. Lotus Sutra says:

To enter the room of the Tathagata is to have great compassion for all living beings. To wear the robe of the Tathagata is to be gentle and patient. To sit on the seat of the Tathagata is to contemplate the emptiness of all things.

In the parable of the thirsty man, a man goes to a high flat area to dig for water to quench his thirst. When he finds the soil dry, he knows that the water is still far away, so he continues to dig. When he strikes damp soil, he knows that water is near. In the same way, when a bodhisattva makes an effort to practice, he can be sure that he is approaching truth. In this way, the sutra unflaggingly promotes bodhisattva practice.

First of all, when we look at chapter 10, “Teachers of the Dharma,” the emphasis on bodhisattvas as apostles of the Buddha or Tathagata is remarkable. That is, those who receive and disseminate even a single phrase of Dharma after the death of the Buddha are regarded as apostles of the Buddha, commissioned by the Buddha to save all living beings in this world, and extolled as “apostles of the Tathagata.”

The latter part of the chapter promotes entering the Tathagata’s room, wearing the Tathagata’s robe, sitting on the Tathagata’s seat, and preaching Dharma without hesitation. The Tathagata’s room, robe, and seat are said to be compassion, patience, and realization of the emptiness of things. Compassion involves treating others with affection and kindness. Patience means enduring without holding things against others. And realization of the emptiness of things means being freed from attachments and placing oneself within the vast and infinite world. These concisely express the attitude a follower of the bodhisattva way holds toward life. Later these came to be valued as the three ways of propagating the sutra.

For some Small Vehicle Buddhists, compassion is an act of being engaged with this world, while the realization of emptiness is a state that goes beyond it, and so compassion should be discarded in order to realize emptiness. But chapter 10 of the Lotus Sutra teaches the unity of compassion and emptiness.

We can understand from this that realization of emptiness is taken positively as a norm for practice in this world. Here too we can see an example of the positive understanding of emptiness found in Mahayana Buddhism.

The number of disciples who are assured of becoming buddhas in the future increases from five hundred to twelve hundred in chapter 8, where we also find the parable of the priceless jewel in the lining of a robe. A good friend told a penniless man that he had sewn a priceless jewel into the lining of his robe when he was drunk. This story is thus about recovery. The poor, drunken man is likened to disciples who had fallen into nihilism, the friend is the Buddha, and the jewel in the lining of the robe is their hidden possibility of becoming buddhas through acts of compassion (bodhisattva practice). We are taught that:

Keeping their bodhisattva actions
As inward secrets,
Outwardly
They appear as shravakas.

Thus the disciples who had fallen into a nihilistic way of life, including the solitary practitioners, were all revived by the Buddha’s call. And they received assurance of becoming buddhas in the future. Chapter 9, which follows, is a summary of this.

Within this group of disciples were some who still had room to learn and some who were regarded as having no further need of study. Those who attained the stage of not having anything more to learn were called arhats. An arhat is a saint who deserves people’s respect and reverence. Essentially, it was another term for the Buddha, used with a positive connotation. But after the rise of Mahayana Buddhism it was often used as a pejorative term for Small Vehicle Buddhists who had become nihilistic because they thought there was nothing more they needed to learn in life.

Such Small Vehicle Buddhists can be regarded as being of two kinds: direct disciples of the Buddha and solitary practitioners. Later, in addition to “Small Vehicle,” it came to be called “the two vehicles.” Be that as it may, what we see in chapter 9 is that all the Small Vehicle Buddhists, both shravakas and pratyekabuddhas, are assured of becoming buddhas in the future whether they are in need of further learning or not. With this the chapter ends. As the text says, “Then the two thousand people in training and no longer in training, hearing the Buddha’s assurance, were ecstatic with joy.” The significance of this is that the form of the Lotus Sutra is such that, through this chapter, the Buddha speaks to his direct disciples, the shravakas. “Two thousand” is just a round number and can be taken to mean all followers of the Small Vehicle.