Christ
went down into the water and it was John who was the minister and baptized him.
And behold ‘the Holy spirit descended as a dove’. It was not a dove which
descended—but the appearance of a dove. Remember what I told you: Christ took
flesh; not the appearance of flesh but its reality; he truly took flesh. But
the Holy Spirit descended from heaven under the appearance of a dove: not in
the reality of a dove, but in its likeness. John saw and believed. (Ambrose of
Milan, “Sermons on the Sacraments,” I.17 in Edward Yarnold, The Awe Inspiring
Rites of Initiation: Baptismal Homilies of the Fourth Century [Slough,
U.K.: St Paul Publications, 1971], 106)