Jerome : But those who have confidence not in their own strength, but in God, and always await His mercy, let them change their strength and go from virtue to virtue: and let them take wings like eagles, and hear: Your youth will be renewed like the eagle's (Psalms 103:5); let them run to the Lord, and not grow weary of desiring Him; let them walk, and never grow faint. We have frequently said that the eagles' old age is rejuvenated by a change of feathers, and only those eagles can look upon the sun's rays and behold the splendor of its shining with sparkling eyes: and they should prove their noble offspring, by means of this experiment. And so even the saints are made young again, and with an immortal body, they do not feel the toil of mortals, but are caught up in the clouds to meet Christ, and never go hungry according to the LXX, because they have the Lord himself as food. — Commentary on Isaiah Theodoret of Cyrus : These things took place at the time of the Jews and the divine apostles. In fact, all those who did not believe were handed over to famine, disease, war and bondage. Those, however, who believed were renewed by the All-Holy Spirit and so imitated the swift flight of eagles. They flew over all the earth, struggling in bodies so foreign to them. — COMMENTARY ON Isaiah 12:40.30