Bellows

Bellows appear in Jeremiah 6:29 in the context of metallurgical refining: The bellows blow fiercely; the lead is consumed by the fire—the refiner's bellows are inadequate to purify the ore, just as the wickedness of Jerusalem cannot be removed by prophetic warning. The bellows used in ancient Near Eastern smelting were typically leather bags that forced air through a clay nozzle into the furnace, creating the high temperatures needed to work copper, bronze, and iron. They represent the human effort that drives the refining process, whether literal or figurative.