God's revelation in the world triggers a fierce cosmic reaction, where the forces of nature respond in sheer awe to His might. Beneath the surface of these stormy natural descriptions lie powerful references to the grand historical miracles that accompanied the Israelites as they left Egypt and journeyed toward the land of Canaan.
The physical world was gripped with terror as the mountains shook violently [מצודת ציון]. The primary approach among commentators links this upheaval to the hidden miracle at the Arnon valleys. There, massive mountains physically uprooted themselves and smashed together, crushing the Amorite armies that lay in ambush within the crevices waiting to attack the Israelites [רש״י, מצודת דוד, צאינה וראינה, אהבת יהונתן]. Alternatively, this shaking is understood as a metaphor. The towering mountains represent the mighty kings of Canaan, who melted into trembling fear when they heard of the wonders God performed for Israel [רד״ק, אברבנאל]. Others view this as a natural phenomenon, describing mountains vibrating from the sheer force of thunder [אבן עזרא], or the earth itself shuddering in dread of the torrential waters about to engulf it [מלבי״ם].
Following this seismic activity, a rushing torrent of water swept through the landscape [מצודת ציון]. Continuing the narrative of the Arnon valleys, some explain that the waters of Miriam's well surged between the newly shifted mountains, washing out the remains of the crushed enemies. This dramatic display revealed the hidden miracle to the Israelites, inspiring them to break into song [מצודת דוד, צאינה וראינה, אהבת יהונתן]. Another historical perspective connects the rushing water to the splitting of the Red Sea and the Jordan River. In those instances, the natural flow of the water ceased and vanished downstream, allowing the Israelites to cross safely on dry land [רש״י, רד״ק, אברבנאל, ביאור שטיינזלץ]. A different approach frames the surging waters as an act of divine retribution, where floods overpowered the mountains to enact vengeance upon enemy nations [אבן עזרא, מלבי״ם].
Amidst the chaos, the watery depths let out a deafening roar [מצודת ציון]. This sound is identified as the crashing of the sea and river as they split apart [אבן עזרא, רד״ק], or the loud rushing of the waters broadcasting the miracle at Arnon [מצודת דוד, צאינה וראינה]. From a more cosmic perspective, when the mountains at Arnon were uprooted, the subterranean depths, normally contained by the weight of the mountains, threatened to rise up and flood the world, roaring in their release [אהבת יהונתן]. It is as if the deep itself was commanding the waters to surge and cover the peaks [מלבי״ם]. On a human level, this roaring voice represents the inhabitants of the earth lifting their voices in praise of God [רש״י], or the overwhelming rumors of God's miracles echoing throughout the entirety of Canaan [אברבנאל].
Finally, a dramatic upward motion completes the scene [מצודת ציון]. Many commentators envision the waters of the Jordan River and the Red Sea halting their flow to stand tall and upright like a massive wall. It appeared as though the watery deep had literally raised its hands, or waves, toward the sky [רד״ק, אברבנאל, מלבי״ם, ביאור שטיינזלץ]. Alternatively, this upward motion creates a contrast between heaven and earth. Just as the inhabitants of the deep praised God, the heavenly hosts above also raised their hands in gratitude [רש״י, אבן עזרא, צאינה וראינה]. Ultimately, this upward gesture reflects a universal recognition of God's supreme might [מצודת דוד], or depicts God Himself raising His hands in mercy, halting the surging depths and saving the world from a catastrophic flood after the mountains had been moved [אהבת יהונתן].