Day 13 covers all of Chapter 8, The Assurance of Future Buddhahood of the Five Hundred Disciples.

Having focused last month on the The Parable of the Priceless Gem, I get to talk about Purna, the son of Maitrayani and foremost in expounding the Dharma. He is not what he seems, a Sravaka.

Although he had the supernatural powers of Bodhisattvas, he performed brahma practices throughout his previous existence. Therefore, the people of the world of the Buddha [under whom he performed brahma practices] thought that he was a Sravaka. He benefited many hundreds of thousands of living beings with this expedient, and also caused innumerable, asamkhya people to aspire for Anuttara-samyak-sambodhi. He did the work of the Buddha, that is, taught all living beings so that the world of the Buddha might be purified.

And in gathas:

Bhisus, listen to me attentively!
The Way practiced by my sons
Is beyond your comprehension
Because they learned how to employ expedients.

Knowing that people wish to hear
The teachings of the Lesser Vehicle,
And that they are afraid of having the great wisdom,
[My sons, that is,] the Bodhisattvas transform themselves
Into Sravakas or cause-knowers,
And teach the people with innumerable expedients.

Saying to the innumerable living beings, [for instance,]
“We are Sravakas.
We are far from the enlightenment of the Buddha,”
They save them, and cause them to attain [Sravakahoodl
Even the lazy people who wish to hear the
Lesser Vehicle Will become Buddhas with this expedient in the course of time.

My disciples are performing
The Bodhisattva practices secretly
Though they show themselves in the form of Sravakas.
They are purifying my world
Though they pretend to want little
And to shun birth-and-death.
In the presence of the people,
They pretend to have the three poisons and wrong views.
They save them with these expedients.
They change themselves into various forms.
If I speak of all their transformations,
The listeners will doubt me.

The remainder of the arhats who are promised future Buddhahood in this chapter all realize “we are Bodhisattvas in reality.”