10 To bring light to the people of this world which We have described, and to lead them back to the pure ideals of the wisdom of the Gospels, there appeared, in the Providence of God, St. Francis of Assisi who, as Dante sang, "shone as the sun" ( Paradiso , Canto XI), or as Thomas of Celano had already written of a similar figure, "he shone forth as a resplendent star on a dark night, like the morning which spreads itself over the darkness." ( Legenda I, No. 37)
Source: Rite Expiatis (Vatican.va)