Song of Solomon 8:7 says what cannot quench love?

Answer: Mighty waters

Song of Solomon 8:7: "Mighty waters cannot quench love; rivers cannot sweep it away" (KJV: "Many waters cannot quench love").

“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 (BSB)