Ohalot, Chapter Eleven, Mishnah Seven
Today’s mishnah deals with a dog who ate the flesh of a corpse and then died on the threshold of a house. His neck is in the house and his stomach, where the piece of flesh is being digested, is outside of the house. The question is: does the impurity enter the house in order to defile all of the contents of the house?
We should note that if the dog was still alive there is no question that a source of impurity found inside him does not defile outside.
A dog which had eaten the flesh of a corpse and then died and was lying over the threshold:
1) Rabbi Meir says: if its neck has a thickness of one handbreadth it can bring the uncleanness, but if not, it does not bring the uncleanness.
2) Rabbi Yose says: we [examine to] see where the uncleanness is. If it is beneath the lintel and inwards, the house becomes unclean; if from the lintel and outwards, the house remains clean.
3) Rabbi Eliezer says: if its mouth [points] inwards, the house remains clean; if its mouth [points] outwards, the house becomes unclean, since the uncleanness goes out through its hind.
a) Rabbi Judah ben Batera says: in either case the house becomes unclean.
4) How long can [the uncleanness] remain in its entrails?
a) Three whole days.
5) [If in the entrails] of fishes or birds, as long as [it takes for the uncleanness] to fall in the fire and be consumed, the words of Rabbi Shimon.
a) Rabbi Judah ben Batera says: in the case of fishes or birds, twenty-four hours.
Section one: Rabbi Meir says that the purity of the house depends on whether the neck is large enough to serve as an ohel. If it is an ohel, then the impurity enters the ohel of the neck and from there spreads to the body. But if the neck is too small to serve as an ohel, the impurity remains in the dog.
Section two: Rabbi Yose says that the size of the neck doesn’t matter. Rather we check to see where in the dog’s body the impurity is found. If it is found inside a part of the body that is in the house, then the house is impure. But if the impurity remains outside of the house, the house is pure.
Section three: Rabbi Eliezer says that the impurity escapes through the dog’s rear end. Therefore, if the rear end is in the house, the house is impure. But if the mouth is in the house, the house is pure.
Rabbi Judah ben Batera says that the impurity can also escape through the dog’s mouth. Therefore, it does not matter which end is in the house, the house is impure.
Section four: The piece of corpse is assumed to be present in the dog’s guts for three whole days. After that it will have been fully digested.
Section five: Flesh eaten by fish or birds does not remain in their (smaller) guts as long as it does for dogs. According to Rabbi Simon, it will remain there only as long as it would take to burn the flesh in a fire. Rabbi Judah ben Batera says that it stays there longer, for an entire day.