Jerome

So that it may be that which is said in the Song of Songs: "You are wholly beautiful, my love, and there is no spot in you." And again: "Behold, you are fair, my near one, behold, you are fair, your eyes are doves." You who are fair and strong, when you have become like him of whom it is sung, "In your beauty and your comeliness," you will hear from the Bridegroom: "Forget your people and your father's house, and the King will desire your beauty."

Homily 61, on Psalm 15 (Alternate Series) ↗

Bede

Behold, you are beautiful, my friend, etc. Behold, you are beautiful in pure works, by which you conduct yourself soberly, justly, and piously in this age. Behold, you are beautiful in the simplicity of heart, because for the sake of the intention of eternity, you persist in good deeds, awaiting the blessed hope and the coming of the glory of the great God. Your eyes are doves, the eyes of your heart are simple and pure, and entirely free from any duplicity of deceit and pretense. …

Commentary on the Song of Songs ↗

Bernard of Clairvaux

"Behold, you are beautiful, my love, behold you are beautiful; your eyes are as doves" (Song 1:15). Beautifully, most excellently, from love, the presumption of the bride; from love, the indignation of the bridegroom. The outcome of the matter proves this. For presumption was followed by correction, correction by amendment, amendment by reward. The beloved is present, the master is removed, the king disappears, dignity is laid aside, reverence is set down. For haughtiness yields where affection grows strong. …

Sermons on the Song of Songs, Sermon 45 ↗