Attributed to Solomon; the attribution can be read several ways in the Hebrew.
When
Disputed, and the language is hard to date.
What it is
Love poetry between a man and a woman, in two voices, with no plot and no mention of God.
What to watch for
Jewish and Christian tradition have long read it as a picture of God and His people; it is also plainly about what it is about. Both readings are old.
Mighty waters cannot quench love; rivers cannot sweep it away. If a man were to give all the wealth of his house for love, his offer would be utterly scorned.Song of Solomon 8:7