Halakhah su Levitico 7:17

Again I saw our sages saying that the shelamim sacrifices were eaten “for two days and one night” (Mishna, Zevahim 5:7). Now if the day began with dawn, it is not possible to have a third day unless there were two nights.³ The limitation to eating the shelamim sacrifice for two days and one night is derived from the verse “What remains from the flesh of the sacrifice on the third day shall be burnt in fire” (Leviticus 7:17). If a day begins with dawn and extends through the night, then it should be permissible to eat the sacrifice through the second night until the morning of the third day. Obviously, the Rabbis were of the opinion that “the third day” began with the evening following the second day.

The commandment of the burning of the remnant (notar) of the [sacrifices]: That we were commanded to burn the notar - and that is meat of the [sacrifices] that remains after the time limited for their eating has passed - as it is stated (Leviticus 7:17), "And the notar of the meat of the sacrifice on the third day, it shall be brunt with fire." And this burning is a positive commandment - as so they say in Mekhilta concerning Pesach (Exodus 12:10), "'You shall not leave any of it, etc., and the notar you shall burn with fire, etc.' - the verse comes to give a positive commandment upon the negative commandment." It is implied that the commandment of burning notar is a positive commandment. And the law of piggul and notar are the same in this, that there is also a positive commandment in its burning, such that we have found Scripture expressing piggul, with the word, notar.