Chullin 251:1

ותני עלה

And in connection with this it was taught that R'Jose declares [the house] clean.

רבי יוסי מטהר

Now to which clause [does R'Jose refer]?

אהייא

If to the last clause-surely the first Tanna [in that case] also declares [the house] clean! It therefore [be this].

אילימא אסיפא ת"ק נמי טהורי קא מטהר

The first Tanna had said: 'If there was some uncleanness in it the house becomes unclean', either by virtue of the fact that the uncleanness must come forth eventually, or by virtue of the rule that concealed uncleanness breaks through.<span class="x" onmousemove="('comment',' I.e., R. Jose had heard the first Tanna declare the house unclean in every case to which one of the reasons stated in the text applies. E.g., (in the case that is inferred from the last clause) where there was not the space of a cubic handbreadth in the drawer, even though the cupboard stood in the doorway of the house, the house is unclean because of concealed uncleanness; or, the case quoted in the first clause, the house is unclean for the uncleanness will eventually pass through.');">¹</span>

אלא דקאמר ת"ק טומאה בתוכה הבית טמא אי משום דדרך טומאה לצאת ואי משום דטומאה טמונה בוקעת

Whereupon R'Jose said to him: As for your argument, 'The uncleanness must come forth eventually', [I reply that] one could take out the uncleanness by halves, or burn it in its place; and as for your ruling, 'Concealed uncleanness breaks through', [I maintain that] concealed uncleanness does not break through.

וקא"ל רבי יוסי

I can point out a contradiction in the views of R'Jose.

דקאמרת דרך טומאה לצאת יכול הוא להוציאה לחצאין או לשורפה במקומה ודקאמרת טומאה טמונה בוקעת טומאה טמונה אינה בוקעת

For we have learnt:<span class="x" onmousemove="('comment',' Ohol. XI, 7.');">²</span>

ורמי דר' יוסי אדר' יוסי

If a dog ate the flesh of a corpse and died<span class="x" onmousemove="('comment',' If alive there would be no question at all of uncleanness, for, as already stated (supra 71a) , uncleanness that is swallowed within a living being cannot render unclean.');">³</span>

דתנן

and Jay upon the threshold:<span class="x" onmousemove="('comment',' With its head pointing inside the house.');">⁴</span>

הכלב שאכל בשר מת ומת הכלב ומוטל על האסקופה

R'Meir says.

ר"מ אומר

If its neck was one handbreadth wide, it brings the uncleanness [into the house];<span class="x" onmousemove="('comment',' Since the width of the neck is one handbreadth (even though it is not one handbreadth of space but consists of flesh, vertebrae, arteries etc.) the uppermost side of the neck overshadows as a 'tent' the uncleanness, and seeing that the 'tent' extends into the house it thus leads in the uncleanness.');">⁵</span>

אם יש בצוארו פותח טפח מביא את הטומאה ואם לאו אינו מביא את הטומאה

and if not, it does not bring in the uncleanness.<span class="x" onmousemove="('comment',' For a space with one of its dimensions less than a handbreadth cannot be regarded as a tent with regard to uncleanness. V. Ohol. III, 7.');">⁶</span>

ר' יוסי אומר

R'Jose says.

רואין מכנגד השקוף ולפנים הבית טמא מכנגד השקוף ולחוץ הבית טהור

We must see [where the uncleanness lies]: if it<span class="x" onmousemove="('comment',' Sc., that part of the dog in which the uncleanness happens to be.');">⁷</span>

רבי אלעזר אומר

lies opposite the lintel and inwards,<span class="x" onmousemove="('comment',' I.e., the inner side of the lintel so that the house overshadows the uncleanness.');">⁸</span>

פיו לפנים הבית טהור פיו לחוץ הבית טמא מפני שטומאה יוצאה דרך שוליו

the house is unclean;<span class="x" onmousemove="('comment',' Presumably even though the dog's neck was not one handbreadth wide, for the uncleanness concealed within breaks through, so that the house overshadows the uncleanness.');">⁹</span>

רבי יהודה בן בתירא אומר

but if opposite the lintel and outwards, the house is clean.

בין כך ובין כך הבית טמא

R'Eleazar says.

מאי לאו אאין בצוארו פותח טפח קאי רבי יוסי וש"מ

If its mouth lies inside,<span class="x" onmousemove="('comment',' The uncleanness being in that part of the dog's carcass which is lying outside.');">¹⁰</span>

טומאה טמונה בוקעת

the house remains clean; but if the mouth lies outside,<span class="x" onmousemove="('comment',' The uncleanness being in that part of the dog's carcass which is lying outside.');">¹⁰</span>

אמר רבא

the house is unclean, because the uncleanness passes out by way of its lower parts.<span class="x" onmousemove="('comment',' And therefore one may regard the uncleanness in the dog as extending along the lower parts of the animal (for by this way it would have been evacuated) into the house.');">¹¹</span>

רואין את חלל הטומאה קתני ורבי יוסי בתרתי פליג וקא"ל לר' מאיר

R'Judah B'Bathyra says.

דקאמרת כי יש בצוארו פותח טפח מביא את הטומאה אנן בתר חללה אזלינן

In all circumstances<span class="x" onmousemove="('comment',' Whether the neck was one handbreadth wide or not, and whether the actual uncleanness lay on the inside of the lintel or not, and whether the mouth of the dog lay inside or not.');">¹²</span>

ודקא אמרת (הבית) כולו טמא

the house is unclean.

מכנגד השקוף ולפנים הבית טמא מכנגד השקוף ולחוץ הבית טהור

Now presumably R'Jose deals with the case where its neck was not one handbreadth wide;<span class="x" onmousemove="('comment',' V. supra n. 8.');">¹³</span>

רב אחא בריה דרבא מתני לה בהדיא רבי יוסי אומר

hence you can deduce [that he holds], concealed uncleanness breaks through! - Said Raba: He [R'Jose] means to say: 'We must consider the space in connection with the uncleanness';<span class="x" onmousemove="('comment',' Where there is in the neck a space of one handbreadth, the uppermost side of the neck would serve as a 'tent' and would lead the uncleanness into the house. Where, however, there is no space of a handbreadth in the neck, even though the neck in which the uncleanness lies is entirely within the house, the house is clean, for the uncleanness is concealed and cannot break through.');">¹⁴</span>

רואין את חלל הטומאה

and R'Jose consequently differs on two points, saying to R'Meir thus: As for your saying: 'If its neck was one handbreadth wide it brings in the uncleanness', [I maintain that] we must consider only the space; and as for your saying, [If it lies] anywhere upon the threshold<span class="x" onmousemove="('comment',' Even if it lies on that part of the threshold which is outside of the lintel.');">¹⁵</span>

ומאן תנא דפליג עליה

the house is unclean, [I maintain that] if it li on the inside of the lintel the house is unclean, but if on the outside of the lintel the house remains clean.<span class="x" onmousemove="('comment',' R. Jose therefore is in every respect less strict than R. Meir, and not, as was previously assumed, more so.');">¹⁶</span>

רבי שמעון הוא דתניא ר"ש אומר

R'Aha the son of Raba actually quotes the Mishnah with these words: R'Jose says. We must consider the space in connection with the uncleanness. And who is the Tanna that disagrees with R'Jose?<span class="x" onmousemove="('comment',' I.e., who is it that holds, in opposition to R. Jose, that overshadowing is in no way included in the expression 'he who touches', for contact and overshadowing are separate categories of uncleanness.');">¹⁷</span> - It is R'Simeon, For it was taught: R'Simeon says.