that it renders impure everything within it, and this is the halakha even if it is full of mustard seeds, in which case most of the seeds do not come in contact with the sides of the vessel, and nevertheless all the mustard seeds become impure.

Rav Adda bar Ahava said to Rava: And let it be derived that an earthenware vessel becomes impure from contact of an impure item with its outer side by means of an a fortiori inference: If all the other types of vessels, which do not become impure from the presence of an impure item in their airspace, become impure from contact of an impure item with their outer side, then with regard to an earthenware vessel, which becomes impure from the presence of an impure item in its airspace, isn’t it logical that it will become ritually impure from contact of an impure item with its outer side?

The Gemara answers: Therefore, the verse states: “And every open vessel that has no sealed cover upon it is impure” (Numbers 19:15), indicating that its impurity is dependent upon the mouth of the vessel. Which is the vessel whose impurity hastily takes effect just after the impure item enters into its mouth? You must say that is an earthenware vessel. And it is when there is no sealed cover on it that the vessel becomes impure. But when there is a sealed cover on it, the vessel is pure, as the earthenware vessel does not become impure from contact of an impure item with its outer side.

The Gemara suggests: And let it be derived that all the other vessels become impure from the presence of an impure item in their airspace by means of an a fortiori inference: If an earthenware vessel, which does not become impure from contact of an impure item with its outer side, becomes impure from the presence of an impure item in its airspace, then with regard to all the other vessels, which become impure from contact of an impure item with their outer side, isn’t it logical that they will become ritually impure from the presence of an impure item in their airspace?

The Gemara answers: Therefore, the verse states with regard to the carcasses of creeping animals: “And every earthenware vessel into which [tokho] any of them falls” (Leviticus 11:33), from which it is inferred: Tokho, i.e., the airspace, of this earthenware vessel renders the vessel impure, and not tokho, the airspace, of any other kind of vessel.

The Gemara objects: How can the halakha be derived from the term tokho in that verse? But didn’t the Sages interpret these instances of tokho that appear in that verse and derive: Just as in the case of tokho that is stated with regard to transmitting impurity, the food is impure even though it did not come into contact with the vessel, so too, in the case of tokho that is stated with regard to the vessel becoming impure, the vessel is impure even though the impure item did not come into contact with it.

The Gemara explains: Four instances of the term tokho from which halakhot can be derived are written: “Tokho” is written, and tokh could have been written; those are two instances. Then, later in that verse, once again “tokho” is written, and tokh could have been written.

One instance is to teach the halakha itself, that the vessel renders the food in its airspace ritually impure, and one instance is to teach the verbal analogy from which it is derived that the vessel becomes impure without contact with the impure item; and one source is to teach that tokho, the airspace, of this earthenware vessel renders the vessel impure, and not tokho of any other kind of vessel; and one source is to teach tokho, food in the airspace of an impure earthenware vessel becomes impure, but not tokh tokho, not food that is in the airspace of a vessel that is within an earthenware vessel, and even if that inner vessel is one of the other types of vessel purified through rinsing in the water of a ritual bath.

The Gemara asks: And let it be derived that all the other vessels do not become impure from contact of an impure item with their outer sides, but rather from the presence of an impure item inside them and with contact with their inner sides by means of an a fortiori inference: If an earthenware vessel, which becomes impure from the presence of an impure item in its airspace, does not become impure from contact of an impure item with its outer side, then with regard to all the other vessels, which do not become impure from the presence of an impure item in their airspace, isn’t it logical that they do not become impure from contact of an impure item with their outer side?

The Gemara answers: Therefore, the verse states: “And every open vessel that has no sealed cover upon it is impure” (Numbers 19:15), from which it is derived: This earthenware vessel (see Leviticus 11:33) is the one that when there is not a sealed cover upon it, it is impure, but when there is a sealed cover upon it, it is pure. But with regard to all the other vessels, whether there is a sealed cover upon them or whether there is not a sealed cover upon them, they become impure.

MISHNA: That which is ritually pure in wooden vessels is ritually impure in metal vessels; that which is ritually pure in metal vessels is ritually impure in wooden vessels.

GEMARA: The Sages taught in explanation of the mishna: Unfinished [golmei] wooden vessels that are receptacles and are fit for use but work remains to complete their crafting are susceptible to becoming impure. Flat wooden utensils are not susceptible to impurity. Unfinished metal vessels are not susceptible to impurity. Flat metal utensils are susceptible to becoming impure. It is found that that which is ritually pure in wooden vessels is ritually impure in metal vessels; that which is ritually pure in metal vessels is ritually impure in wooden vessels.

And these are the unfinished wooden vessels: Any vessel that one plans in the future to smooth, to set gems or ornaments in it, to plane it, to adorn it with grooves and protuberances, to rub it and smooth it with the skin of a tuna [tunas], or if it is lacking a base or a rim or a handle, the vessel is susceptible to becoming impure. If the vessel is lacking the hollowing necessary to render it a receptacle, it is not susceptible to impurity.

The Gemara asks: Isn’t it obvious that if the vessel is lacking hollowing, it is not susceptible to becoming impure, as it is clearly not a vessel? The Gemara answers: No, it is necessary only in a case where one hollowed three log [kefiza] in a receptacle that he intends to hold one kav, which contains six log. Even though it is a receptacle, since the receptacle is incomplete it is not susceptible to impurity.

And these are the unfinished metal vessels: Any vessel that one plans in the future