Now when all the people were baptized, it came to pass, that when Jesus also was baptized, and praying, the heaven was opened,
All Commentaries on Luke 3:21 Go To Luke 3
Ambrose of Milan
AD 397
Why like a dove? For the grace of the washing requires simplicity, so that we may be innocent like doves. The grace of the washing requires peace, as in an earlier image the dove brought to the ark that which alone was inviolable by the flood. He of whom the dove was the image, who now deigned to descend in the form of a dove, taught me that in that branch, in that ark, was the image of peace and of the church. In the midst of the floods of the world the Holy Spirit brings its fruitful peace to its church. David too taught, he who perceived the sacrament of baptism and said with the Spirit of prophecy, “Who will give me wings like a dove?” Exposition of the Gospel of Luke