Day 13 covers all of Chapter 8, The Assurance of Future Buddhahood of the Five Hundred Disciples.
Having last month learned of Pūrṇa’s future as a Buddha named Dharma-Brightness, we hear from twelve hundred Arhats.
Thereupon the twelve hundred Arhats, who had already obtained freedom of mind, thought:
“We have never been so joyful before. How glad we shall be if we are assured of our future Buddhahood by the World-Honored One just as the other great disciples were!”
Seeing what they had in their minds, the Buddha said to Maha-Kāśyapa:
“Now I will assure these twelve hundred Arhats, who are present before me, of their future attainment of Anuttara-samyak-saṃbodhi one after another. My great disciple Kauṇḍinya Bhikṣu, who is among them, will make offerings to six billion and two hundred thousand million Buddhas, and then become a Buddha called Universal-Brightness, the Tathāgata, the Deserver of Offerings, the Perfectly Enlightened One, the Man of Wisdom and Practice, the Well-Gone, the Knower of the World, the Unsurpassed Man, the Controller of Men, the Teacher of Gods and Men, the Buddha, the World-Honored One. The others of the five hundred Arhats, including Uruvilvā-Kāśyapa, GayaKāśyapa, Nadī-Kāśyapa, Kālodāyin, Udāyin, Aniruddha, Revata, Kapphina, Bakkula, Cunda, and Svāgata, also will attain Anuttara-samyak-saṃbodhi, and become Buddhas also called Universal-Brightness.”
See Early Disciples