The Interpretation of that Passage of the Canticles
Consider now, O virgins, that, in saying to the bride, “You have ravished my heart, my sister, my spouse,” He shows the clear eye of the understanding, when the inner man has cleansed it and looks more clearly upon the truth. For it is clear to every one that there is a twofold power of sight, the one of the soul, and the other of the body. But the Word does not profess a love for that of the body, but only that of the understanding, saying, “You have ravished my heart with one of your eyes, with one chain of your neck;”which means, By the most lovely sight of your mind, you have urged my heart to love, radiating forth from within the glorious beauty of chastity.
Now the chains of the neck are necklaces which are composed of various precious stones; and the souls which take care of the body, place around the outward neck of the flesh this visible ornament to deceive those who behold; but those who live chastely, on the other hand, adorn themselves within with ornaments truly composed of various precious stones, namely, of freedom, of magnanimity, of wisdom, and of love, caring little for those temporal decorations which, like leaves blossoming for an hour, dry up with the changes of the body.
For there is seen in man a twofold beauty, of which the Lord accepts that which is within and is immortal, saying, “You have ravished my heart with one chain of your neck;”meaning to show that He had been drawn to love by the splendour of the inner man shining forth in its glory, even as the Psalmist also testifies, saying, “The King's daughter is all glorious within.”
Source: The Banquet of the Ten Virgins (New Advent)