(Bamidbar 31:23) "Every thing that comes into the fire shall you pass through the fire": Knives, spits, and grills are whitened in fire. Pots, stew-pots, and kettles and boilers are to be boiled against absorption of idolatrous elements. "And every thing that does not come into the fire": such as spears, cups and flasks, are rinsed and immersed. And whence is (the need for) immersion (derived)? It follows a fortiori, viz.: If what does not require sprinkling (with the waters of the red heifer) requires immersion, how much more so that which requires sprinkling!