אהלות י׳Oholot 10

Mishnah 1א׳

אֲרֻבָּה שֶׁהִיא בְתוֹךְ הַבַּיִת וְיֶשׁ בָּהּ פּוֹתֵחַ טֶפַח, טֻמְאָה בַבַּיִת, כְּנֶגֶד אֲרֻבָּה טָהוֹר. טֻמְאָה כְנֶגֶד אֲרֻבָּה, הַבַּיִת טָהוֹר. הַטֻּמְאָה בֵּין בַּבַּיִת וּבֵין כְּנֶגֶד אֲרֻבָּה, נָתַן אֶת רַגְלוֹ מִלְמַעְלָן, עֵרֵב אֶת הַטֻּמְאָה. מִקְצָת טֻמְאָה בַבַּיִת וּמִקְצָתָהּ כְּנֶגֶד אֲרֻבָּה, הַבַּיִת טָמֵא, וּכְנֶגֶד הַטֻּמְאָה טָמֵא:

A hatch that is inside a house and has in it a handbreadth's space, if there is impurity in the house, opposite the hatch is pure. If the impurity was opposite the hatch, the house is pure. Whether the impurity is in the house or opposite the hatch, if someone placed his foot on top of it, he combines the impurity. If part of the impurity was in the house and part of it was opposite the hatch, the house is impure and opposite the hatch is impure.

Mishnah 2ב׳

אֵין בָּאֲרֻבָּה פּוֹתֵחַ טֶפַח, טֻמְאָה בַבַּיִת, כְּנֶגֶד אַרֻבָּה טָהוֹר. טֻמְאָה כְנֶגֶד אֲרֻבָּה, הַבַּיִת טָהוֹר. הַטֻּמְאָה בַבַּיִת, נָתַן אֶת רַגְלוֹ מִלְמַעְלָן, טָהוֹר. הַטֻּמְאָה כְנֶגֶד אֲרֻבָּה, נָתַן אֶת רַגְלוֹ מִלְמַעְלָן, רַבִּי מֵאִיר מְטַמֵּא. וַחֲכָמִים אוֹמְרִים, אִם טֻמְאָה קָדְמָה אֶת רַגְלוֹ, טָמֵא. אִם רַגְלוֹ קָדְמָה אֶת הַטֻּמְאָה, טָהוֹר. רַבִּי שִׁמְעוֹן אוֹמֵר, שְׁתֵּי רַגְלַיִם, זוֹ עַל גַּב זוֹ, שֶׁקָּדְמוּ אֶת הַטֻּמְאָה, מָשַׁךְ הָרִאשׁוֹן אֶת רַגְלוֹ וְנִמְצָא רַגְלוֹ שֶׁל שֵׁנִי שָׁם, טָהוֹר, מִפְּנֵי שֶׁקָּדְמָה רַגְלוֹ שֶׁל רִאשׁוֹן אֶת הַטֻּמְאָה:

If the hatch does not have a handbreadth's space, if there is impurity in the house opposite the hatch is pure. If there is impurity opposite the hatch, the house is pure. If the impurity is inside the house and he placed his foot on top of it, he is pure. If the impurity is opposite the hatch and he placed his foot on top of it, Rabbi Meir declares him impure but the Sages say if the impurity preceded his foot he is impure, but if his foot preceded the impurity he is pure. Rabbi Shimon says, two feet, one on top of the other, that preceded the impurity, if the first withdrew his foot and the second foot was still there it is pure because the first foot came before the impurity.