ישעיהו, פרק ל״ד, פסוק ג׳

A harsh picture of destruction emerges following a massive slaughter, where the scale of death is so vast that the dead are denied the basic human dignity of a burial. A distinction is made between the types of casualties: some are warriors struck down by the sword on the battlefield, while others are the general dead who perish inside the city limits [מלבי״ם]. Regardless of where they fall, these bodies will be cast into the streets and roads, left entirely abandoned on the ground without anyone to bury them [מצודת דוד, שד״ל].

Because these bodies are left in the open, a terrible stench will rise from the countless corpses piled upon one another [מצודת ציון, אברבנאל, שטיינזלץ]. Adding a deeply tragic layer to this scene, even inside the cities—where there is no active enemy to prevent a proper burial—the foul smell will still rise simply because there will be no survivors left to bury the dead [מלבי״ם].

The imagery concludes with a striking, poetic exaggeration, an interpretation agreed upon by the commentators. The sheer volume of spilled blood will be so immense that it will appear as though the mountains themselves are melting away into the blood [מצודת דוד, אברבנאל]. Alternatively, the blood will flood the earth so deeply that it rises to reach the very peaks of the mountains [מלבי״ם].