The bride Moses loved the Bridegroom in the same way as the virgin in the Song who says, Let him kiss me with the kisses of his mouth; and through the face-to-face converse accorded him by God (as the Scripture testifies [cf Num 12.8]), he became after these theophanies more intensely desirous of such kisses, praying to see the object of his yearning as if he had never glimpsed him. In the same way, none of the others in whom the divine yearning was deeply lodged ever came to a point of rest in their desire. And even as now the soul that is joined to God is not satiated by her enjoyment of him, so too the more abundantly she is filled up with his beauty, the more vehemently the longings abound. For since the words of the Bridegroom are “spirit and life” (John 6.63), and everyone who is joined to the Spirit becomes spirit, while everyone who is attached to life “passes from death to life” (John 5.24) according to the Lord’s word, it follows that the virgin soul longs to approach the fount of the spiritual life. That fount, however, is the mouth of the Bridegroom, whence “the words of eternal life” (John 6.68) as they gush forth fill the mouth that is drawn to it, just as the prophet does when drawing spirit though his mouth (cf Ps 118.31 LXX=119.131). Since then it is necessary for the one who draws drink from the fount to fix mouth to mouth, and the fount is the Lord who says, “If anyone thirst, let him come to me and drink” (John 7.37), it follows that the soul, thirsty as she is, wills to bring her own mouth to the mouth that pours out life, saying, Let him kiss me with the kisses of his mouth.
St Gregory of Nyssa, Homily 1. The Church’s Bible: The Song of Songs. Translation by Richard A. Norris, Jr