Day 5 begins Chapter 3, A Parable.

Last month, I discussed some questions I have regarding the prediction given to Sariputra and his reign as a Buddha called Flower-Light in a world called Free-From-Taint in a kalpa called Great-Treasure-Adornment.

While I may be puzzled, Śāriputra is not.

Thereupon Śāriputra, who felt like dancing with joy, stood up, joined his hands together, looked up at the honorable face, and said to the Buddha:

Hearing this truthful voice of yours, I feel like dancing [with joy]. I have never felt like this before. Why is that? We [Sravakas and the Bodhisattvas] heard this Dharma before. [At that time] we saw that the Bodhisattvas were assured of their future Buddhahood, but not that we were. We deeply regretted that we were not given the immeasurable insight of the Tathagata.

World-Honored One! I sat alone under a tree or walked about mountains and forests, thinking, ‘We [and the Bodhisattvas] entered the same world of the Dharma. Why does the Tathagata save us only by the teachings of the Lesser Vehicle?’

Now I understand that the fault was on our side, not on yours, because if we had waited for your expounding of the Way to Anuttara-samyak-sambodhi, we would have been saved by the Great Vehicle. When we heard your first teaching, we did not know that that teaching was an expedient one expounded according to our capacities. Therefore, we believed and received that teaching at once, thought it over, and attained the enlightenment [to be attained by that teaching].

World-Honored One! I reproached myself day and night [after I saw that the Bodhisattvas were assured of their future Buddhahood]. Now I have heard from you the Dharma that I had never heard before. I have removed all my doubts. I am now calm and peaceful in body and mind. Today I have realized that I am your son, that I was born from your mouth, that I was born in [the world of] the Dharma, and that I have obtained the Dharma of foe Buddha.

And in gathas:

I once was attached to wrong views,
And became a teacher of the aspirants
for the teaching of Brahman.
You expounded to me the teaching of Nirvana,
And removed my wrong views because you understood me.
I gave up all those wrong views,
And attained the truth that nothing is substantial.

At that time I thought
That I had attained extinction.
But now I know
That the extinction I attained is not the true one.
When I become a Buddha in the future,
I shall be adorned with the thirty-two marks,
And respected
By gods, men, yaksas, and dragons.
Only then I shall be able to say
That I have eliminated all [illusions].

In the midst of the great multitude,
You said to me, “You will become a Buddha.” Hearing this truthful voice,
All my doubts are gone.

There is a reason Sariputra is considered foremost in wisdom among voice hearers and why Nichiren chose to include him on the Mandala Gohonzon.

From the book Lotus World:

In the Lotus Sutra, the voice-hearers fall into three groups of superior capacity, intermediate capacity, and lesser capacity, depending on the manner in which they are able to understand the One Vehicle. Śāriputra represents the superior category. He is able to understand the Buddha’s teaching of the reality of all things, the declaration of the One Vehicle in Chapter 2 of the Lotus Sutra, and receives the Buddha’s prediction that he will become Flower Light Tathagata in Chapter 3.