Day 21 covers all of Chapter 16, The Duration of the Life of the Tathāgata.

Again, there is a wealth of material here but on the first time through with my one-topic limit I have to begin at the beginning.

Thereupon the Buddha said to the great multitude including Bodhisattvas and others, ‘Good men! Understand my sincere and infallible words by faith!’

He said to the great multitude again, ‘Understand my sincere and infallible words by faith!’

He said to them once again, ‘Understand my sincere and infallible words by faith!’

What’s going to be said just can’t be understood without faith.

As the Buddha explains in Chapter 2, Expedients:

The Dharma cannot be shown.
It is inexplicable by words.
No one can understand it
Except the Buddhas
And the Bodhisattvas
Who are strong in the power of faith.

And in Chapter 3, A Parable, the Buddha repeats:

Even you, Sariputra,
Have understood this sutra
Only by faith.
Needless to say,
The other Sravakas cannot do otherwise.
They will be able to follow this sutra
Only because they believe my words,
Not because they have wisdom.

Again and again we learn of those who “received this sutra by faith” and “understood it by faith.”

Faith in the past, faith today and faith tomorrow.