St. Nicholas of Serbia. From the book: Missionary Letters

In an ancient folk legend, it is said that in times gone by, swallows did not know how to move to warm regions in the cold season. And, when the snow fell and frost hit, they severely suffered and died. Seeing this, one compassionate man took pity on them and began to do everything that he knew and knew in order to teach the swallows to fly to the south. He gave them signs - the swallows did not understand them, he beckoned to them with food towards the south - did not help, frightened and drove them - in vain. Nothing happened to him. Then he began to pray to God that He would make him a swallow. God fulfilled his desire and turned a man into a swallow who could think and feel like a man. Then the swallow man easily explained himself with the swallows and led them away in the warmer autumn.
Since then, the swallows have learned to fly to the south. Of course, this is only a poetic fiction. But let him help us, at least to some extent, understand how the eternal Wisdom, born of eternal Love, incarnated and became a Man among people, to be led, by the earthly bitterness, to a new path, to warmer lands, in the The Kingdom of God: "Where there is neither illness, no sorrow, no sighing." But even in the small, human body, the great Lord remained Jehovah, Unchanging, Eternal. Always the way He was from eternity in the boundlessness of His Kingdom and His ineffable glory.

St. Nicholas of Serbia. From the book: Missionary Letters