Bede

Because your voice is sweet, etc. Indeed, the voice of that soul is sweet to the Lord, which knows how either to announce the words of the Lord to neighbors or to resound praises to the Lord Himself sweetly with the prophet, How sweet are your words to my taste, sweeter than honey to my mouth (Psalm 119)! …

Commentary on the Song of Songs ↗

Bernard of Clairvaux

"My dove in the clefts of the rock, in the hollows of the wall" (Song 2:14). Not only in the clefts of the rock does the dove find a safe refuge; she finds it also in the hollows of the wall. But if by the wall we understand not a heap of stones, but the communion of saints, let us see whether perhaps he has called the hollows of the wall the places, as it were left empty, of the angels who fell through pride: inasmuch as these are to be filled up from among men, as ruins to be repaired from living stones. …

Sermons on the Song of Songs, Sermon 62 ↗

Robert of Tombelaine

By the holes of the rock, moreover, I would gladly understand the wounds of the hands and feet of Christ hanging on the cross. And the cavity of the wall I would interpret in the same sense as the wound in his side made by the lance. And rightly is the dove said to be in the holes of the rock and in the cavity of the wall, because while it imitates the patience of Christ in the remembrance of the cross, while it recalls those very wounds to memory for the sake of example, just as a dove in the holes of a rock, so the simple soul …

Commentary on the Song of Songs, Chapter 2 ↗