Rashi on Leviticus 19:8/רש"י על ויקרא י״ט:ח׳

1ואכליו עונו ישא THEREFORE EVERYONE THAT EATETH IT SHALL BEAR HIS INIQUITY — Scripture is speaking here of flesh actually left unburnt on the third day (so that this verse must be connected with v. 6, and not with v. 7) since one is not liable to excision for eating that which was slaughtered with the intention to eat its flesh outside the prescribed place (of which v. 7 is speaking), because Scripture has already excluded such a case from the penalty of excision (cf. Rashi v. 7). This verse must therefore be speaking of actual נותר. In Treatise Keritot 5a they (our Rabbis) derived it (the fact that v. 8 refers back to נותר in 5:6) from a verbal analogy.