Day 22 covers all of Chapter 17, The Variety of Merits.

Having last month repeated in gāthās the benefits to be received for believing for just a moment, we consider those who have firm faith.

Those who firmly believe [my longevity ],
And have no doubts about it
Even for a moment,
Will be able to obtain more merits [than he].

The Bodhisattvas who have practiced the Way
For the past innumerable kalpas,
Will believe my longevity
When they hear of it.

They will receive this sūtra on their heads,
And wish:
“May we live long and save all living beings
Just as the World-Honored One of today,
Who is the King of the Śākyas, [saves them]
By expounding the Dharma without fear
At the place of enlightenment
With [a voice like] a lion’s roar!
When we sit at the place of enlightenment,
Respected by all living beings,
May we preach that we also shall live
As long [as the World-Honored One of today]!”

Those who have firm faith,
And who are pure and upright,
And who hear much and memorize all teachings,
And who understand my words
According to their meaning,
Will have no doubts [about my longevity].

“Furthermore, Ajita! Those who hear of my longevity of which I told you, and understand the meaning of my words, will be able to obtain innumerable merits, which will help them attain the unsurpassed wisdom of the Tathāgata. Needless to say, those who hear this sūtra, cause others to hear it, keep it, cause others to keep it, copy it, cause others to copy it, or offer flowers, incense, necklaces, banners, streamers, canopies, perfumed oil, and lamps of butter oil to a copy of it, will be able to obtain immeasurable merits. These merits will help them obtain the knowledge of the equality and differences of all things.

See Believing in a Righteous Faith and Endeavoring To Practice It