A vivid picture of ultimate destruction unfolds through the metaphor of a boiling pot of meat left on a raging fire until nothing remains. The imagery captures a continuous, unrelenting process of adding fuel, stoking the flames, and boiling the contents down to absolute ruin. The primary approach among commentators is that the constant piling on of wood and the intensifying of the fire represent God multiplying the troubles upon the people [רש״י, רד״ק, מלבי״ם, מצודת דוד]. The ultimate goal of this intense heat is total consumption and destruction [מצודת ציון]. Because of the massive fire and prolonged boiling, the meat inside the pot shrinks, falls away from the bone, and completely loses its original form. It mixes into the broth, eventually breaking down into a thick, uniform paste [רש״י, מלבי״ם, ביאור שטיינזלץ].
As the reduction process reaches its peak, the imagery shifts to the blending of a spice mixture. One perspective views this as the final step of normal cooking, where spices are stirred in only after the food has boiled down [רש״י, מצודת דוד]. In a symbolic sense, just as a fully cooked and spiced dish is perfectly prepared to be eaten, the inhabitants of the city, worn down by endless hardships, are now completely ripe and ready to be consumed by the sword [רד״ק]. Another perspective suggests that this does not refer to adding outside spices at all. Instead, it describes the physical state of the food itself, which has dissolved and been ground down into a fine texture resembling a milled spice blend [מלבי״ם, ביאור שטיינזלץ].
The final and most devastating stage of the process involves the scorching of the bones. The descriptions of burning indicate extreme dryness and charring from heavy heat [רש״י, מצודת ציון, רד״ק]. Once all the liquid in the pot evaporates, the remaining contents are ruined. The fierce heat trapped inside the vessel burns and dries out even the hard bones until they turn completely black and begin to smoke [רש״י, מצודת דוד, מלבי״ם, ביאור שטיינזלץ]. Symbolically, these charred bones represent the leaders and the most powerful figures of the city. Just like the rest of the contents, they too will fail to survive the intense heat of the disaster and will face total destruction [רד״ק].