The śrāvaka disciples such as Ānanda, and Rāhula, who were guaranteed to be future Buddhas in the theoretical section of the Lotus Sūtra through the three cycles of the Buddha’s preaching (dharma, parable, and past relationships) had learned the Lotus Sūtra far in the past, 3,000 dust-particle kalpa (aeons) ago, from a bodhisattva who was the 16th prince of the Great Universal Wisdom Buddha, namely Śākyamuni Buddha today. Nevertheless, due to evil karma they abandoned the Lotus Sūtra, embracing such Mahayana sutras as the Flower Garland Sūtra, Wisdom Sūtra, Sūtra of Great Assembly, Nirvana Sūtra, Great Sun Buddha Sūtra, Revealing the Profound and Secret Sūtra, and Sūtra of Meditation on the Buddha of Infinite Life or Hinayana Āgama sutras. While doing so, they gradually declined in status to the realms of heavenly and human beings and finally to the three evil realms. As a result for as long as 3,000 dust-particle kalpa they spent much of their time in the Hell of Incessant Suffering, some of their time in the seven major hells, once in a long while in the other one hundred or so hells, and on rare occasions in the realms of hungry souls, beasts, and asura. It was after the 3,000 dust-particle kalpa (aeons) that they were able to be born in the realm of human or heavenly beings.

Therefore, it is stated in the Lotus Sūtra, fascicle 2 (chapter 3), “They will always stay in hell, strolling in it as though it were a garden, and remain in other evil realms as if they were at home.” Those who committed the ten evil acts will fall into such hells as the hell of regeneration and that of black ropes, where they spend 500 or 1,000 years. Those who committed the five rebellious sins, are destined to the Hell of Incessant Suffering for as long as one medium kalpa before being reborn. Those who abandoned the Lotus Sūtra, however, will fall into the Hell of Incessant Suffering and remain there for innumerable number of kalpa, though their sin does not seem to be as terrible as the sin of murdering parents.

Kyōdai-shō, Letter to the Ikegami Brothers, Writings of Nichiren Shōnin, Volume 6, Followers I, Page 73

At the conclusion of Chapter 6, Assurance of Future Buddhahood, the Buddha teases what’s coming next in Chapter 7, The Parable of a Magic City:

Now I will tell you
About my previous existence
And also about yours.
All of you, listen attentively!

What we learn is that Śākyamuni, as one of 16 princes, has been teaching the same people ever since 3,000 dust-particle kalpas ago.

“These sixteen Bodhisattvas willingly expounded the Sūtra of the Lotus Flower of the Wonderful Dharma. Each of them taught six hundred billion nayutas of living beings, that is, as many living beings as there are sands in the River Ganges. Those living beings were always accompanied by the Bodhisattva[, by whom they were taught,] in their consecutive existences. [In each of their consecutive existences,] they heard the Dharma from him, and understood it by faith. By the merits [they had thus accumulated], they were given a privilege to see four billion Buddhas, that is, four billion World­Honored Ones. They have not yet seen all of them.

As I read Nichiren’s explanation of what happened to the śrāvaka disciples such as Ānanda and Rāhula, I ponder whether this is why the Buddha predicts it will take these śrāvakas lengthy kalpas before they complete the way of Bodhisattvas and become Buddhas.

How many times in my past lives have I failed to keep the faith?