Seventy. The Geonim, Rabbi Aharon (may his memory be blessed) and Rabbi Moshe (may his memory be blessed), disagreed regarding the koshering of the oven.

Seventy-one. Large cooking pots that cannot be placed within another vessel and heated with boiling water should have a white-hot stone placed in them, and boiling water from the first vessel should be poured over them, making them equivalent to the first vessel. The stone should then be passed over the entire vessel. This is also the practice regarding the koshering of tables and benches. The table should be rinsed with water first so that the boiling water poured over it does not cool down. In Eliahu Rabbah, it was decided that heating with stones does not effectively kosher vessels, except for a bowl or similar utensils, as most of their use involves being rinsed from the first vessel, unlike items mostly used in the first vessel, for which this method is not effective because it does not truly equate to being a first vessel. In our humble opinion, even for a bowl or similar utensils, it is not advisable to initially use stones for heating, except in cases where it is known that the vessel has not been used in its usual manner as a first vessel.