I'm really enjoying Robert Jenson's commentary on The Song of Songs in the Interpretation series as I read it for a second time. Jenson's approach is very different to contemporary approaches to The Song but that's it's greatest strength. He draws deeply on the church fathers, reformers and others, rooting his interpretation in the history of the church rather than the culture of our day.
His approach is simple and easily accessible in a series designed to equip preachers. He takes The Song passage by passage looking at the overt story, then the theological allegory, and then thirdly an application to marriage.
The Song is taken seriously as a text and the applications in revealing the gospel and to human relationships are outstanding. This on 1:2-4:
"Our poem's soteriology is thus that of the church fathers, especially those in the East - and indeed exposition of the Song was a favourite way for them to describe salvation. Israel does not here long for forgiveness of sin or rescue from disaster or for other gifts detachable from the Giver, as Western theology tends to conceive salvation, but simply for the Lord himself. Moreover, the longing is aesthetic rather than ethical; it is longing for the Lord's touch and kiss and fragrance, The Lord is simply lovable, and salvation is union with him, a union for which sexual union provides an analogy"And then applied to marriage
"If bodily love can be an appointed image of union with God, then we may not suppose that love becomes purer or nobler by disembodiment. If there is such a thing as love that needs no touching, it is not this love that in the Song mirrors the love between Israel's God and his people, whatever may be true of the gods of the religions and the philosophers. During the recent sexual "revolution" those among the mass fornicators who still felt that their practices needed justification sometimes said, "It's only bodies, after all"... precisely such opinion is the most precise self-manifestation of the evil that currently infests us.... The Song knows better: we were made for, and therefore need not only God but the created other, in whom the heart may find some est also penultimately to union with God."You might not agree with everything in this book but you'll find it sane and engaging and enlivening as a way into a book that our forefathers have drawn on to enjoy the gospel but which is sadly neglected or mocked or missed today.
See also Ellen Davis' commentary - Who's being allegorical, eh?