Day 21 covers all of Chapter 16, The Duration of the Life of the Tathāgata.

Day 21 Text with annotations

Having last month concluded Chapter 16, The Duration of the Life of the Tathāgata, we begin again with Śākyamuni telling the congregation to pay attention.

Thereupon the Buddha aid to the great multitude including Bodhisattvas and others, “Good men! Understand my sincere and infallible words by faith!”
He said to the great multitude again, “Understand my sincere and infallible words by faith!”

He said to them once again, “Understand my sincere and infallible words by faith!”

Thereupon the great multitude of Bodhisattvas, headed by Maitreya, joined their hands together and said to the Buddha, “World-Honor done, tell us! We will receive your words by faith.”

They said this three times. Then they said once again, “Tell us! We will receive your words by faith.”

Thereupon the World-Honored One, seeing that they repeated their appeal even after they repeated it three times, said to them:

“Listen to me attentively! I will tell you about my hidden core and supernatural powers. The gods, men and asuras in the world think that I, Śākyamuni Buddha, left the palace of the Śākyas, sat at the place of enlightenment not far from the City of Gayā, and attained Anuttara-samyak-saṃbodhi [forty and odd years ago]. To tell the truth, good men, it is many hundreds of thousands of billions of nayutas of kalpas since I became the Buddha. Suppose someone smashed into dust five hundred thousand billion nayuta asaṃkhya worlds, which were each composed of one thousand million Sumeru-worlds, and went to the east [carrying the dust with him). When he reached a world at a distance of five hundred thousand billion nayuta asaṃkhya worlds [from this world], he put a particle of dust on that world. Then he went on again to the east, and repeated the putting of a particle of the dust [on the world at every distance of five hundred thousand billion nayuta asaṃkhya worlds] until the particles of the dust were exhausted. Good men! What do you think of this? Do you think that the number of the world he went through is conceivable, countable, or not?”

Maitreya Bodhisattva and others said to the Buddha:

“World-Honored One! Those worlds are innumerable, uncountable, inconceivable. No Śrāvaka or Pratyekabuddha could count them even by his wisdom-without-āsravas. We are now in the state of avaivartika, but cannot, either. World-Honored One! Those worlds are innumerable.”

Thereupon the Buddha said to the great multitude of Bodhisattvas:

“Good Men! Now I will tell you clearly. Suppose those worlds, whether they were marked with the particles of the dust or not, were smashed into dust. The number of the kalpas which have elapsed since I became the Buddha is on hundred thousand billion nayuta asaṃkhyas larger than the number of the particles of the dust thus produced. All this time I have been living in this Sahā-World, and teaching [the living beings of this world] by expounding the Dharma to them. I also have been leading and benefiting the living beings of one hundred thousand billion nayuta asaṃkhya worlds outside this world.

Nichiren comments on what happened when the Eternal Buddha was revealed in his letter, A Treatise :Revealing the Spiritual Contemplation and the Most Verable One:

[W]hen the Eternal Buddha was revealed in the essential section of the Lotus Sūtra, this world of endurance (Sahā World) became the Eternal Pure Land, indestructible even by the three calamities of conflagration, flooding, and strong winds, which are said to destroy the world. It transcends the four periods of cosmic change: the kalpa of construction, continuance, destruction, and emptiness. Śākyamuni Buddha, the Lord-preacher of this Pure Land, has never died in the past, nor will He be born in the future. He exists forever throughout the past, present, and future. All those who receive His guidance are one with this Eternal Buddha. It is because each of our minds is equipped with the “3,000 modes of existence” and the “three factors,” namely, all living beings, the land in which they live, and the five elements of living beings (matter, perception, conception, volition and consciousness).

This truth was not made clear in the first fourteen chapters of the theoretical section of the Lotus Sūtra. Perhaps it was because the time was not ripe at this stage of preaching the Lotus Sūtra; and capacity of comprehension on the part of the listeners was not yet sufficient.

Kanjin Honzon-shō, A Treatise Revealing the Spiritual Contemplation and the Most Verable One, Writings of Nichiren Shōnin, Doctrine 2, Page 148

Day 20 completes Chapter 15, The Appearance of Bodhisattvas from Underground, and concludes the Fifth Volume of the Sutra of the Lotus Flower of the Wonderful Dharma.

Day 20 Text with annotations

Having last month considered Maitreya Bodhisattva’s puzzlement about the great Bodhisattva-mahāsattvas who sprang up from underground, we consider further Maitreya’s puzzlement.

Some great Bodhisattvas are each accompanied by attendants
Sixty thousand times as many as the sands of the River Ganges.
They are seeking the enlightenment of the Buddha
With all their hearts.

The number of these great teachers is sixty thousand times
The number of the sands of the River Ganges.
They came together and made offerings to you.
Now they protect and keep this sūtra.
The attendants or disciples accompanying
Each [of the other great Bodhisattvas] number
Fifty thousand times or forty thousand times
Or thirty thousand times or twenty thousand times
Or ten thousand times or a thousand times
Or a hundred times as many as the sands of the River Ganges,
Or a half, a third, or a quarter
Of the number of the sands of the River Ganges,
Or as many as the sands of the River Ganges Divided by a billion;
Or ten million nayuta, a billion or fifty million,
Or a million, ten thousand, a thousand or a hundred,
Or fifty, ten, three, two or one.
[The great Bodhisattvas] who are accompanied
By less attendants are even more numerous.
Some [great Bodhisattvas] have no attendants
Because they prefer a solitary life.
They are the most numerous.
They came together to you.

No one will be able to count
All [these great Bodhisattvas] even if he uses
A counting wand for more kalpas
Than the number of the sands of the River Ganges.

These Bodhisattvas have
Great powers, virtues and energy.
Who expounded the Dharma to them? Who taught them?
Who qualified them to attain [perfect enlightenment]?

Under whom did they begin to aspire for enlightenment?
What teaching of the Buddha did they extol?
What sūtra did they keep and practice?
What teaching of the Buddha did they study?

These Bodhisattvas have supernatural powers
And the great power of wisdom.
The ground of this world quaked and cracked.
They sprang up from under the four quarters of this world.

World-Honored One!
I have never seen them before.
I do not know
Any of them.

They appeared suddenly from underground.
Tell me why!
Many thousands of myriads
Of millions of Bodhisattvas
In this great congregation
Also want to know this.

There must be some reason.
Possessor of Immeasurable Virtues!
World-Honored One!
Remove our doubts!

Nichiren addresses these doubts in his letter Open Your Eyes to the Lotus Teaching:

Grand Master Miao-lê further explained in his Annotations on the Words and Phrases of the Lotus Sūtra, “Wise men know things in advance as a snake knows that it is a snake.” The meaning of these words in the Lotus Sūtra and annotations by T’ien-t’ai and Miao-lê are clear, that is to say, nobody had ever seen or heard of those bodhisattvas from the earth after Śākyamuni’s enlightenment under the bodhi tree till today, either in this world or in any of the worlds in the universe.

So the Buddha answered the question of Bodhisattva Maitreya: “Maitreya! It was I who taught and guided those great bodhisattvas whom you said you had never seen. After I attained perfect enlightenment in this Sahā World, I taught, guided, and controlled them, and encouraged them to aspire for enlightenment.” He continued, “After I sat in meditation under the bodhi tree near the town of Gayā and was able to attain perfect enlightenment, I taught and guided them, while preaching the supreme dharma and caused them to aspire for enlightenment. Now they have all been proceeding to the highest enlightenment without falling back I have taught and guided them since the eternal past.”

Then Bodhisattva Maitreya and other great bodhisattvas began to doubt the Buddha. At the time the Flower Garland Sūtra was preached, numerous great bodhisattvas such as Dharma Wisdom gathered. While wondering who they were, Maitreya and others were told by Śākyamuni Buddha, apparently to their satisfaction, that Dharma Wisdom and other great bodhisattvas were Śākyamuni’s “good friends.” The same thing happened to those great bodhisattvas who gathered together at Daihōbō where the Sūtra of the Great Assembly was preached, and to those who gathered at Lake White Heron upon the preaching of the Wisdom Sūtra. The great bodhisattvas appearing from underground now, however, seemed incomparably superior to them, and it appeared probable that they were teachers of Śākyamuni Buddha. Nevertheless, the Buddha declared that it was He who caused them to aspire for enlightenment, as if the Buddha taught and guided immature people as His disciples. It was only natural, therefore, that Bodhisattva Maitreya and others had serious doubts about Śākyamuni Buddha.

Kaimoku-shō, Open Your Eyes to the Lotus Teaching, Writings of Nichiren Shōnin, Doctrine 2, Page 72

Day 19 concludes Chapter 14, Peaceful Practices, and begins Chapter 15, The Appearance of Bodhisattvas from Underground.

Day 19 Text with annotations

Having last month considered how Śākyamuni is like the king who rewards his soldiers’ efforts, we consider why Śākyamuni teaches this sūtra lastly.

“Mañjuśrī! This Sutra of the Lotus Flower of the Wonderful Dharma is the most excellent and profound teaching of all the Tathāgatas. Therefore, I expound it lastly just as the powerful king gave the brilliant gem lastly, the one which he had kept [in his topknot) for a long time.

“Mañjuśrī! This Sutra of the Lotus Flower of the Wonderful Dharma is the treasury of the hidden core of the Buddhas, of the Tathāgatas. It is superior to all the other sūtras. I kept it [in secret] and refrained from expounding it for the long night. Now I expound it to you today for the first time.”

Nichiren comments on this in Selecting the Right Time:

It is said in the Lotus Sūtra, fascicle 5 (chapter 14): “This Lotus Sūtra is the secret treasure of all Buddhas. It is supreme of all sūtras.” Please note that “it is supreme of all sūtras.” According to this sūtra, therefore, he who insists that the Lotus Sūtra is supreme of all sūtras is a true practicer of the Lotus Sūtra, isn’t he? Nevertheless, many who are revered in the land insist that there are sūtras superior to the Lotus. Standing against these monks, who are revered by the king and his subjects, the practicer of the Lotus Sūtra is poor and powerless, with all the people in the land despising him. Under such circumstances, if he points out their sin of slandering the True Dharma as stubbornly as Never Despising Bodhisattva or as decisively as Commentator Bhadraruci defeated Brahman, the Boaster, his life will be in jeopardy. This seems of prime importance. This fits me, Nichiren.

Senji-shō, Selecting the Right Time: A Tract by Nichiren, the Buddha’s Disciple, Writings of Nichiren Shōnin, Doctrine 1,
Page 250-251