Day 10 concludes Chapter 6, Assurance of Future Buddhahood, and opens Chapter 7, The Parable of a Magic City.

In the remainder of Chapter 6, Assurance of Future Buddhahood, Great Maudgalyayana, Subhuti, Maha-Katyayana and “the five hundred disciples of mine” received predictions of their future attainment of Buddhahood after making offerings to billions of Buddhas and completing the Way of Bodhisattvas.

The chapter ends with this teaser:

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

That previous existence was a long, long time ago:

According to my remembrance,
There lived a Buddha, an Honorable Biped,
Called Great-Universal-Wisdom-Excellence,
Countless kalpas ago.

Suppose someone smashed
All the earth-particles
Of one thousand million Sumeru-worlds
Into ink-powder.

He went, [carrying the ink-powder with him,]
And inked a dot as large as a particle of dust
On the world at a distance of one thousand worlds.
He repeated the inking until the ink-powder was exhausted.

Suppose the worlds
Through which he went,
Whether they were inked or not,
Were smashed into dust.

It is innumerable kalpas,
More than the number
Of the particles of dust thus produced,
Since that Buddha passed away.

More important, given that time frame:

I remember the extinction of that Buddha
As vividly as if he had passed away just now,
By my unhindered wisdom; I also remember
The Sravakas and Bodhisattvas who lived [with him].

Great-Universal-Wisdom-Excellence tried for ten small kalpas to attain Anuttara-samyak-sambodhi. Gods and heavenly kings made offerings in order to help.

At the end of the period of ten small kalpas, the Dharma of the Buddhas came into the mind of Great-Universal-Wisdom-Excellence Buddha.

Great-Universal-Wisdom-Excellence had 16 sons before becoming a Buddha. Upon hearing their father had attained Buddhahood, the sons gave up their playthings, left home, and came to that Buddha. The sons praised the Buddha and urged him to Expound the Dharma:

You, the World-Honored One, know
What all living beings have deep in their minds,
What teachings they are practicing,
And how much power of wisdom they have.
You know their desires, the merits they obtained,
And the karmas they did
In their previous existence.
Turn the wheel of the unsurpassed Dharma!