The human love story between man and woman became The Song of Songs, only because of the other, sublime poetry behind it.
Were it not for the heavenly love–the earthly love would have expressed only a cry of biological craving.
What raises the physical yearning is the loftier craving for which the human physical love serves as an allegory.
Even when the lovers are not aware of it, their love includes in it something more, elements that they cannot define to themselves.
The biology of desire is very direct, very simple—and in and of itself, quite uninteresting.
But here, because there is something beyond it, the love cry exceeds its purpose as an instrument for the satisfaction of physical desire—it becomes a song-poem.
And in a wider scope, since the love between the lover and his beloved is really a material symbol of the entire love of a people and, more than that, of the entire world, the song is lifted up, gains dimensions of another greatness and scope in which matter ceases to be only physical, and becomes the material bearer of other essences.
–Rabbi Adin Steinsaltz
In "The Song of Songs," in On Being Free by Rabbi Adin Steinsaltz