Day 17 covers all of Chapter 12, Devadatta, and opens Chapter 13, Encouragement for Keeping this Sutra.

Sakyamuni explains a past life lesson:

I remember that I became a kjng in a kalpa of the past.
Although I was a king,
I did not indulge in the pleasures of the five desires
Because I was seeking the Great Dharma.

I tolled a bell, and said loudly in all directions;
“Who knows the Great Dharma?
If anyone expounds the Dharma to me,
I will become his servant.”

There was a seer called Asita.
He came to [me, who was] the great king, and said:
“I know the Wonderful Dharma.
It is rare in the world.
If you serve me well,
I will expound the Dhanna to you.”

Hearing this, I had great joy.
I became his servant at once.
I offered him
Anything he wanted.

I collected firewood and the fruits of trees and grasses,
And offered these things to him respectfully
from time to time.
I never felt tired in body and mind
Because I was thinking of the Wonderful Dhanna.

I sought the Great Dharma strenuously
Because I wished to save all living beings.
1 did not wish to benefit myself
Or to have the pleasures of the five desires.

Although I was the king of a great country,
1 sought the Dharma strenuously.
I finally obtained the Dharma and became a Buddha.
Therefore, I now expound it to you.

And the kicker:

The seer at that time was a previous life of Devadatta. Devadatta was my teacher. He caused me to complete the six paramitas. He caused me to have loving-kindness, compassion, joy and impartiality. … I attained perfect enlightenment and now save all living beings because Devadatta was my teacher.

Not only that, but Devadatta will even become a Buddha and expound the Wonderful Dharma to all living beings. From teacher in a past life to enemy in the present life to Buddha in a future.

Good men or women in the future who hear this chapter of Devadatta of the Sutra of the Lotus Flower of the Wonderful Dharma with faithful respect caused by their pure minds, and have no doubts [about this chapter], will not fall into hell or the region of hungry spirits or the region of animals. They will be reborn before the Buddhas of the worlds of the ten quarters. They will always hear this sutra at the places of their rebirth. Even when they are reborn among men or gods, they will be given wonderful pleasures. When they are reborn before the Buddhas, they will appear in lotus-flowers.

And we still have the story of Manjushri’s efforts to expound the Dharma in the realm of the dragon king.

Accumulated-Wisdom asked Manjusri:

“The sutra is exceedingly profound and wonderfu1. This is the treasure of all the sutras. It is rare in the world. Do you know anyone who acted according to this sutra so strenuously that he has already been qualified to become a Buddha quickly?”

Manjusri answered:

“Yes. There is a daughter of Dragon-King Sagara [among those whom I taught]. She is eight years old. She is clever. She knows the karmas of all living beings. She obtained dharanis. She keeps all the treasury of the profound and hidden core expounded by the Buddhas. She entered deep into dhyana-concentration, and understood all teachings. She aspired for Bodhi in a ksana, and reached the stage of irrevocability. She is eloquent without hindrance. She is compassionate towards all living beings just as a mother is towards her babe. She obtained all merits. Her thoughts and words are wonderful and great. She is compassionate, humble, gentle and graceful. She [has already been qualified to] attain Bodhi[, and to become a Buddha quickly].”

Despite objections:

Accumulated-Wisdom Bodhisattva said:

“As far as I know, [when he was a Bodhisattva,] Sakyamuni Buddha sought Bodhi, that is, enlightenment incessantly for innumerable kalpas. He accumulated merits by practicing austerities. Even the smallest part, even the part as large as a poppy-seed of this world – this world being composed of one thousand million Sumeru-worlds – is not outside the places where the Bodhisattva made efforts to save all living beings at the cost of his life. It was after doing all this that he attained Bodhi, that is, enlightenment. I do not believe that this girl will be able to attain perfect enlightenment[, that is, to become a Buddha] in a moment.”

And…

Thereupon Sariputra said to the daughter of the dragon-king:

“You think that you will be able to attain unsurpassed enlightenment [and become a Buddha] before long. This is difficult to believe because the body of a woman is too defiled to be a recipient of the teachings of the Buddha. How can you attain unsurpassed Sodhi? The enlightenment of the Buddha is far off. It can be attained only by those who perform the [Bodhisattva] practices with strenuous efforts for innumerable kalpas. A woman has five impossibilities. She cannot become 1. the Brahman-Heavenly-King, 2. King Sakra, 3. King Mara, 4. a wheel-turning-holy-king, and 5. a Buddha. How can it be that you, being a woman, will become a Buddha, quickly [or not]?”

But she proved them wrong:

Thereupon the congregation saw that the daughter of the dragon-king changed into a man all of a sudden, performed the Bodhisattva practices, went to the Spotless World in the south, sat on a jeweled lotus-flower, attained perfect enlightenment, obtained the thirty-two major marks and the eighty minor marks [of the Buddha], and [began to] expound the Wonderful Dharma to the living beings of the worlds of the ten quarters. Having seen from afar that [the man who had been] the daughter of the dragon-king had become a Buddha and [begun to] expound the Dharma to the men and gods in his congregation, all the living beings of the Saha-World, including Bodhisattvas, Sravakas, gods, dragons, the [six other kinds, that is, in total] eight kinds of supernatural beings, men, and nonhuman beings, bowed [to that Buddha] with great joy.

Although that joy was muted for some:

The Accumulated-Wisdom Bodhisattva, Sariputra, and all the other living beings in the congregation received the Dharma faithfully and in silence.

The remainder of the day covered the start of Chapter 13, Encouragement for Keeping this Sutra.

While “Medicine-King Bodhisattva-mahasattva and Great-Eloquence Bodhisattva-mahasattva, together with their twenty thousand attendants who were also Bodhisattvas” vowed to expound the sutra in the Saha-World after the Buddha’s extinction, the Arhats and Sravakas offered only to do so in “some other worlds rather than the Saha-World.”

Maha-Prajapatr Bhiksuni, the sister of the mother of the Buddha, and six thousand bhiksunis, as well as Yasodhara Bhiksuni, the mother of Rahula, received assurances of their future Buddhahood, but they too would only expound the Lotus Sutra in some other world.