The Lord, therefore, your scriptural imagination can tell you, wants to kiss your lips with a passion, to redden them with the redness of his passion for you. The “scarlet thread” of the beloved’s lips, stained by the blood of the Lord’s passion and inflamed by the heat of his kisses, belongs to the Lord’s church and, by extension, to each of its members. The Lord’s death on the cross is the deepest kiss of humanity’s unclean lips (reflecting Isa. 6:5), extending to all the embrace given to Abraham. Christians reciprocate this kiss most fully here below in drinking the blood-red wine of the Eucharist. The stain of that wine on our lips is the mark of the Lord’s blood on our bodies; it is also the mark of his lips on ours, cleaning them with the purifying flame of his passion.
– Paul Griffiths, Song of Songs (Brazos Theological Commentary on the Bible), Kindle Loc. 1433