Ps 102:5

“And that the writer was speaking of baptism is evident from the very words in which it is stated that it is impossible to renew to repentance those who were fallen, inasmuch as we are renewed by means of the laver of baptism, whereby we are born again, as Paul says: "For we are buried with him through baptism into death, that, as Christ rose from the dead through the glory of the Father, so we, too, should walk in newness of life." And in another place: "Be renewed in the spirit of your mind, and put on the new person that is created after God." And elsewhere again: "Your youth shall be renewed like the eagle," because the phoenix after death is born again from its ashes, as we being dead in sin are through the sacrament of baptism born again to God and created anew. So, then, here as elsewhere, he teaches one baptism. "One faith," he says, "one baptism."”

“But let us speak of death as common to all people. Why should we be afraid of it, when it generally does not harm the soul? For it is written, "Do not be afraid of those who kill the body but cannot kill the soul." Now through death the soul is freed, while it separates itself from the dwelling place of the body and divests itself of the wrappings of disquiet. And so let us too, while we are in the body, following the way of death, raise up our bodies from this fleshly couch and arise from the tomb, as it were. Let us withdraw from the bond of the body and leave all things whatsoever that are of earth, so that when the adversary comes he may find nothing of his in us. Let us strive for the eternal and fly up to the divine on the wings of love and the oars of charity. Let us rise up from here, that is, from the things of the age and those of the world. For the Lord has said, "Arise, let us go from here," teaching that each one should arise from the earth, raise up his soul that lies on the ground, lift it to the things that are above and call forth his eagle, the eagle of whom it is said, "Your youth will be renewed like the eagle's."”

“However, rightly so, a man has not many, but two feet; for four feet belong to wild animals and beasts, and two to birds. Therefore, a man is like a bird, who seeks lofty things with his sight and flies with a certain stroke of the senses' keenness. And therefore it is said about him: Your youth will be renewed like the eagle's; because he is closer to heavenly things and higher than eagles, who can say: But our conversation is in heaven.”

“Brothers, let your holiness keep in mind that I recently preached this, namely that a person should be remolded into a younger age through righteousness, and though wearied by the weakness of old age he should be born again into childhood by the character of innocence in such a way that we may see old people become infants again by the mystery that intervenes, for there is a certain renewal in ceasing to be what you were and to take up what you had previously been. I say, there is renewal, which is also why neophytes receive their name, because in some newness they cast off the spots of oldness and have received the grace of innocence, as the apostle says, "Put off the old person with his deeds and put on the new person, who was created in the image of God." Thus also holy David says, "Your youth will be renewed like that of an eagle." He understands that the perishable things of our life can be revived through the grace of baptism and that that which had fallen by the oldness of sins can be renewed by a certain youthfulness. But that you may understand that the prophet is speaking about the grace of baptism, he compared the renewal itself to an eagle, a bird which is said to lead a long life by constantly changing its appearance and to grow young with a new set of wings when the old feathers are dying off, in such a way that it clothes itself with a revived newness of clothing as it puts off its old plumage. Thus we understand that it is not the limbs but rather the feathers of the eagle that feel old age. Therefore, it clothes itself anew, and as feathers sprout up anew, the old mother is turned back into a chick. Then she must be compared to chicks, since she with shining feathers must plan inexperienced flights and restrain her once experienced beatings of her wings as if she were a newborn, idle bird in the nest. For although she knows how to fly from her past practice, she nonetheless has little confidence because of the thinness of her feathers. Therefore, the holy psalmist prophesied this concerning the grace of baptism. Our neophytes, recently baptized, have (like eagles) put off the old skin and taken on the new clothing of holiness and are adorned with the revived grace of immortality as with light feathers, while their old blemishes die off, so that in them the dead sins of old age grow old, but life des not grow old, for like an eagle turned back into a chick, they have been called back to infancy. They know about how to live in this age, but they have the carefree state that comes from the healing of righteousness.”

“After the battle, then, I shall be crowned; after the crown, what shall I do? "He who satisfieth thy longing with good things" [Psalm 103:5]. ...Seek thy own good, O soul. For one thing is good to one creature, another to another, and all creatures have a certain good of their own, to the completeness and perfection of their nature. There is a difference as to what is essential to each imperfect thing, in order that it may be made perfect; seek for thy own good. "There is none good but One, that is, God." [Matthew 19:17] The highest good is thy good. What then is wanting unto him to whom the highest good is good? For there are inferior goods, which are good to different creatures respectively. What, brethren, is good unto the cattle, save to fill the belly, to prevent want, to sleep, to indulge themselves, to exist, to be in health, to propagate? This is good to them: and within certain bounds it hath an allotted measure of good, granted by God, the Creator of all things. Dost thou seek such a good as this? God giveth also this: but do not pursue it alone. Canst thou, a coheir of Christ, rejoice in fellowship with cattle? Raise thy hope to the good of all goods. He will be thy good, by whom thou in thy kind hast been made good, and by whom all things in their kind were made good. For God made all things very good. ...”