The mountains melted from before the Lord
The inhabitants of them, through fear, the Lord going before Israel in a pillar of cloud and fire, and delivering mighty kings and their kingdoms into their hand:
[even] that Sinai from before the Lord God of Israel;
or, "as that Sinai", the note of similitude being wanting; and the sense is, the mountains melted, just as the famous mountain Sinai in a literal sense did, when it trembled and quaked at the presence of God on it; the tokens of it, the fire and smoke, thunders, lightnings, and tempests there seen and heard; and which being observed, would call to mind the benefit Israel then received, which required praise and thankfulness, as well as would serve to express the awe and reverence of God due unto him.