The powerful imagery of mountains reacting to the Divine presence serves to connect the immediate miracles of the battlefield with the monumental historical revelation at Mount Sinai. By recalling the past, the narrative highlights the enduring kindness and wonders God performs for Israel. The same divine providence that allowed the Israelites to receive the Commandments continues to protect them in their current struggles [רלב״ג, מלבי״ם].
When God appears, the physical world reacts with overwhelming awe. Commentators offer varying perspectives on how the mountains responded to this encounter. Some describe a reaction born of pure terror, where the mountains trembled so violently that they seemed to drip with sweat [מצודת דוד, מצודת ציון]. The primary approach among commentators takes this further, explaining that the sheer dread of God's presence caused the solid, unyielding peaks to appear as though they were melting and dissolving into flowing water [רש״י, מלבי״ם, ביאור שטיינזלץ]. Another perspective suggests a physical uprooting. In this view, the mountains were dislodged and moved from place to place, driven by a deep yearning for the Torah to be given upon their slopes [אלשיך].
This dramatic upheaval of nature is not just a historical reflection but a powerful metaphor for the enemies of Israel. Just as the earth shook in the past, the inhabitants of Canaan now trembled, melted, and dissolved in fear as God fought on behalf of His people [רד״ק].
The specific mention of Sinai acts as a direct call to remember that great event. It invites the listener to reflect on how that very mountain smoked, burned, and shook when God descended upon it [רש״י]. Yet, alongside this view, a unique contrast emerges regarding Sinai itself. While the surrounding mountains melted, dissolved, or violently shifted out of fear during the giving of the Torah, Mount Sinai remained entirely unchanged. Because it was the chosen site where Israel received the Torah and God became their God, He cherished Sinai. He granted it a special, enduring strength to stand firm and resolute, completely unaffected by the overwhelming awe that consumed the rest of the natural world [אלשיך].