2,469. Immersing Purchased Utensils
Maachalos Assuros 17:5
Immersing meal ware that was purchased from non-Jews in order to permit it for eating and drinking has nothing to do with the laws of ritual purity. Rather, it’s a rabbinic enactment based on Numbers 31:23: “Everything that can be passed through fire, pass it through fire and it will be pure.” Our oral tradition teaches that this verse refers to purifying vessels from non-Jewish cooking rather than from ritual impurity. This is because there’s no form of impurity that’s purified through fire. Those who are ritually unclean are purified through immersion and corpse impurity is purified through sprinkling the water with the ashes of the red heifer; fire doesn’t enter into it. It is, however, relevant to purifying vessels from non-Jewish cooking. Our verse says “it will be pure,” so the Sages added another form of purity to it aside from passing it through fire in order to permit it from non-Jewish cooking.
Maachalos Assuros 17:6
The Sages only required immersion for metal meal utensils that were purchased from a non-Jew. If someone borrows them from a non-Jew, or if a non-Jew left them as security for a loan, they must only be scrubbed, boiled or purged in fire as appropriate; one need not immerse them. Likewise, if one bought utensils of wood or stone, he need only scrub, boil or purge them as appropriate. Earthenware utensils do not require immersion unless they’re coated with lead, in which case they’re considered like metal utensils.