The mythologies of the ancient Near East often represented the powers of chaos in the world as flood waters, often using an expression like many waters.
The young woman is therefore saying that the power of love can stand up to even the mighty powers of chaos in the universe.1 The Lord’s flame is not extinguished by the many waters, nor is the flame of human love.2
There are several notable verbal parallels between these verses (Song of Solomon 8:6–7) and Isaiah 43:2, where the Lord promises protection for his people when they pass through the dangers of many waters and threatening flames. Even though enough water can normally put out a fire, not even the most fearful threats in this world can overwhelm the power of love.3
7 Many waters cannot quench love, neither can floods drown it. If a man offered for love all the wealth of his house, he would be utterly despised.