Explanation of a Verse in Shir HaShirim

To the esteemed inquirer, 

As I understand it, the meaning is as the holy Rashi explains: this verse is a metaphor for Klal Yisrael's love for Hashem. The phrase "If a man would give" means, if someone were to rise and attempt to bribe or entice the Jewish people to exchange their love for Hashem, they—not only would they not accept the bribe, but they would despise the one who offered such an exchange, treating him with contempt. In other words, there is not even the slightest possibility of such an exchange. This is Rashi's explanation: "Many waters" — the nations and "rivers" — their princes and kings would not be able to wash it away. Through strength and fear, or through enticement and seduction: "If a man would give all the wealth of his house to exchange your love, they would despise him." All these witnesses, Hashem and His court, testify that thus Klal Yisrael clings to its beloved. 

With blessing, Rav Nachum