"Many waters have lifted their voices." There was a story about Hadrian who wanted to stand at the edge of the ocean, so he took ropes and was dragged for three years. He heard a voice saying "End, Hadrian." He then asked what the waters were murmuring to God. He made glass boxes and put people inside them and threw them into the ocean. The people inside the boxes went up and said, "We heard the ocean murmuring great things in the heights."
Another saying is that the rivers have lifted their voices to God. Woe to the wicked who think that the Land of Israel belongs only to themselves and not to others. Rivers refer to the waves, as it is said, "Woe to the many peoples" (Isaiah 17:12), which means the waves that will beat down and oppress Israel in their troubles. And now the enemies will come, and they too will be oppressed. "Woe to the many rivers that beat down." "Many waters" refer to the upper waters, while "many waters" below are called "the great waters of the sea." Just as a king who had two regiments, when he visited one, they would say, "This regiment is great because the king visited it." And when he visited the other, they would say the same. Similarly, when the Lord is above, the upper waters are called "many waters," and when he descends below, the lower waters are called "many waters," as it says, "The waters were exceedingly strong" (Psalm 93:4).