He Christ is the splendor of eternal glory, "the brightness of eternal light, and the mirror without cloud."
Behold, I say, the birth of this mirror. Behold Christ's poverty even as he was laid in the manger and wrapped in swaddling clothes. What wondrous humility, what marvelous poverty! The King of angels, the Lord of heaven and earth resting in a manger! Look more deeply into the mirror and meditate on his humility, or simply on his poverty. Behold the many labors and sufferings he endured to redeem the human race. Then, in the depths of this very mirror, ponder his unspeakable love which caused him to suffer on the wood of the cross and to endure the most shameful kind of death. The mirror himself, from his position on the cross, warned passers-by to weigh carefully this act, as he said: "All of you who pass by this way, behold and see if there is any sorrow like mine." Let us answer his cries and lamentations with one voice and one spirit: "I will be mindful and remember, and my soul will be consumed within me."
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Saint Clare of Assisi from a letter to Blessed Agnes of Prague