Beatrice no longer smiles at Dante as they ascend toward the heaven of Saturn because as she explains --
"[If my] radiance were untempered, it would sear
Thy mortal power, as a thunderbolt will smite
The foliage from a branch and leave it bare."
(Canto XXI. 10-12)
Dante sees the descent of numerous holy souls till one brilliant soul approaches Dante who asks him why there is no singing on Saturn. The answer given "We forbear to sing, as Beatrice forbears to smile likewise." (Canto XXI. 62-63) Dante asks the brilliant soul why he alone was chosen by God to speak. The soul explains,
"The thing thou ask'st is plunged so deep in the night
Of the eternal statue's dark abyss
It is cut off from all created sight."
(Canto XXI. 94-96)
"And where they shape the skyline humpback-wise
Is Catria; below, a hermitage ...
Through heat and cold serenely did I live
On meager food, seasoned with olive-oil,
Dwelling content in thoughts contemplative."
(Canto XX. 109-110, 112-114)
With these words Dante begins to identify the holy soul who is speaking to him. He is St. Peter Damian who entered the Benedictine Hermitage of Fonte Avellana located on the slopes of Mt. Catria in the Italian region of Umbria. There he became its abbot in 1041 A.D. We know that Dante was a guest of this Hermitage and there met Peter Damian
"My mortal span of life was almost o'er
When I was called and dragged unto the Hat
Which passing downwards ever sinketh lower."
It was Pope Stephen IX who in 1057 AD convinced him to become the Cardinal-bishop of Ostia. He only accepted this post in 1058 AD after the pope threatened him with excommunication and being commanded under the virtue of obedience. Dante's following passages reflect the Saint desire to reform Church discipline. In his day some Cardinals were preoccupied with rare and costly clothing, fine horses and armed escorts of which he disapproved.
In his teaching he stressed the Omnipotence of God. This does not mean that God can do anything whatsoever. For example, he cannot lie because lying is an evil thing. "By "omnipotence", Damian means this ability to do anything that is good." What is evil in a being is a lack of perfection which should be there and this was not done by God. "However, the characterization of omnipotence as God's ability to bring about anything that he can will, reveals an important aspect in Damian's view of divine power, viz. divine freedom. Damian is very emphatic about God's freedom in his creative activity. In his omnipotence, God can do anything that is good, but he need not do everything that is good -- he need not do anything at all...." (Stanford Encyclopedia of Philosophy)
This canto ends with these holy souls clustering around St. Peter Damian crying aloud in a manner that "greatly surpassed all mortal din" so that Dante became frightened.
Canto XXII: Saturn - Contemplatives, St. Benedict