Komentarz do Kapłańska 6:21

ישבר [BUT AN EARTHEN VESSEL WHEREIN IT IS SODDEN] SHALL BE BROKEN — because the substance absorbed in it becomes what is known as נותר (the technical term for any portion of a sacrifice not eaten by the time prescribed for this) (cf. Avodah Zarah 76a). That, too, is the regulation applicable to all sacrifices (i. e. that an earthen vessel wherein they have been cooked must be broken).

חרס אשר תבושל בו ישבר, “and an earthenware vessel which it has been cooked in must be broken.” This means that the boiling of the meat must also take place in the sacred precincts, just as the washing had to take place in sacred precincts.

Becomes נותר(meat left overnight that is invalid and must be burnt). After the day and the night that follows it. You might ask: Leave it until after daybreak on the morrow when it [the taste absorbed in the vessel’s wall] will give a bad taste (נותן טעם לפגם) and it will not require breaking or scouring! The answer is: Since at daybreak on the morrow the obligation to break or scour is immediate, it does not lapse afterwards (Re’m). With regard to Re’m’s question I stood trembling and astonished. Why is he raising such a difficulty? It is only with respect to [the prohibition of] eating, which depends on the taste of the forbidden food, that it is permitted when it gives a bad taste, since [in this case] he does not benefit. This is not so concerning נותר, which has to be burnt — the main mitzvah of burning is even after its taste has gone bad and it was left longer than its time period. As long as it is in the world he is required to burn it. How would the fact that the taste has gone bad help in this case? Therefore, the Torah commands to break the earthenware vessels and scour and rinse copper vessels so that they will not come to the circumstance of having a bad taste and of being נותר at the time of daybreak. This is because it is prohibited to bring something to the condition of becoming נותר so that it will have to be burnt. How would having a bad taste help to nullify the mitzvah of burning the נותר? It was not that the Torah said the earthenware vessel needs to be broken because it will discharge [the taste of נותר] into the food that is cooked in it afterwards, for certainly, even if he wants to leave it and not cook anything in it afterwards it does not help. Rather, he would be transgressing by causing נותר and he blemishes that which is holy. Therefore, he needs to break the earthenware pot since it is not possible to burn the absorptions of נותר in it (Divrei Dovid).