The Song of Solomon, as part of God's inspired Word, is much more than an ancient erotic poem, as some have interpreted it. Solomon was given great wisdom by God, so that he "spake three thousand proverbs; and his songs were a thousand and five" (1 Kings 4:32). Of these latter, he apparently considered this to be his masterpiece, his "song of songs" (Song 1:1). It can best be understood as a pure love song describing the courtship and marriage of Solomon and his first bride, long before he later married "many strange |that is, 'foreign'| women" (1 Kings 11:1), who "turned away his heart after other gods" (1 Kings 11:4).
Another interpretation, favored by many Bible scholars over the centuries, is that the story is an allegory whose theme is the love of Christ and His heavenly bride, the true church.
That is, it really does seem to describe the love of young Solomon and his first bride. Such love had and still has God's blessing, for the union of man and woman in permanent, loving marriage, has always been God's plan, ever since Adam and Eve (note Christ's confirmation of this in Matthew 19:3-9). It is "the works of the flesh," including adultery and fornication, which God condemns.
But the song can also bring great blessing to the reader as he sees therein the eternal love of the Lord Jesus and His heavenly Bride. Our text verse, read in this light, is a glorious truth. Not even the waters of a great flood could quench such love, nor all the possessions of a wealthy king ever purchase it. It is true eternal love, bought by the blood of the Bridegroom and received with undying faith by His beloved Bride. HMM