Halacha

הלכה א
אָדָם שֶׁהֶאֱהִיל בְּיָדוֹ אַחַת עַל הַמֵּת וְהֶאֱהִיל בַּשְּׁנִיָּה עַל הַכֵּלִים אוֹ שֶׁנָּגַע בְּמֵת וְהֶאֱהִיל עַל הַכֵּלִים אִם יֵשׁ בְּיָדוֹ פּוֹתֵחַ טֶפַח הַכֵּלִים טְמֵאִין וְאִם לָאו טְהוֹרִין. וְכֵן שְׁנֵי בָּתִּים וּבָהֶם שְׁנֵי חֲצָאֵי זֵיתִים וּפָשַׁט יָדוֹ לְבַיִת זֶה וְיָדוֹ הַשְּׁנִיָּה לַבַּיִת הַשֵּׁנִי אִם יֵשׁ בְּיָדוֹ פּוֹתֵחַ טֶפַח עֵרֵב אֶת הַטֻּמְאָה וְנַעֲשָׂה הַכּל כְּאֹהֶל אֶחָד וְנִטְמָא הוּא וְהַבָּתִּים. וְאִם לָאו אֵינוֹ מֵבִיא אֶת הַטֻּמְאָה:
כסף משנה
1.
The following rules apply when a person held one hand over a corpse and one hand over keilim or he touched a corpse and held his hand over keilim. If each of his hands cover a handbreadth of space, the keilim are impure. If they are smaller, they are pure.
Similarly, if there are two buildings near each other and there is a portion of a corpse the size of half an olive in each of them and a person inserted one hand into one building and the other into the second building, if each of his hands cover a handbreadth of space, he has joined the impurity together. Everything is considered as one ohel and he and the buildings are impure. If they are smaller, he does not join the impurity together.

הלכה ב
אָדָם שֶׁהִשְׁקִיף בְּעַד הַחַלּוֹן וְהֶאֱהִיל עַל הַטֻּמְאָה מֵבִיא אֶת הַטֻּמְאָה לַבַּיִת וְנִטְמָא כָּל הַבַּיִת. הָיָה מֻטָּל עַל הָאַסְקֻפָּה וּמִקְצָתוֹ בְּתוֹךְ הַבַּיִת וּמִקְצָתוֹ בַּחוּץ וְהֶאֱהִילָה טֻמְאָה עַל מִקְצָתוֹ שֶׁבַּחוּץ הַבַּיִת טָמֵא. מִפְּנֵי שֶׁהָאָדָם חָלוּל וְיֵשׁ בּוֹ גֹּבַהּ טֶפַח וְכֵיוָן שֶׁהֶאֱהִילָה טֻמְאָה עָלָיו הֲרֵי זֶה כְּמַאֲהִיל עָלֶיהָ וּמֵבִיא אֶת הַטֻּמְאָה. וְכֵן אִם הָיְתָה טֻמְאָה בַּבַּיִת וְהֶאֱהִילוּ טְהוֹרִין עַל מִקְצָתוֹ שֶׁבַּחוּץ הֲרֵי אֵלּוּ טְמֵאִין מִפְּנֵי שֶׁהוּא כְּמַאֲהִיל עַל הַטֻּמְאָה וְהָאָדָם מֵבִיא וְאֵינוֹ חוֹצֵץ כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
2.
When a person looks out from a window and leans over impurity, he conveys impurity to the house in which he is located. The entire house becomes impure. If he was lying on the doorstep, part of his body being in the house and part being outside the house and impurity was positioned above the portion outside the house, the house is impure, because a person is hollow and the upper portion of his body is a handbreadth high. Since impurity was held over him, it is as if he stood over it and he conveys the impurity.
Similarly, if there was impurity within a house and pure people stood over the portion of a man lying outside, over the doorstep, they are impure. The rationale is that he is considered as if he is covering impurity and a person conveys impurity, but does not intervene against it, as we explained.

הלכה ג
נוֹשְׂאֵי הַמֵּת שֶׁעָבְרוּ בּוֹ תַּחַת הָאַכְסַדְרָה וְהֵגִיף אֶחָד מֵהֶן אֶת הַדֶּלֶת וּסְמָכוֹ בְּמַפְתֵּחַ כְּדֵי שֶׁלֹּא יִטַּמֵּא הַבַּיִת. וְכֵן אִם הָיָה אָדָם מִבִּפְנִים אוֹ מִבַּחוּץ סוֹמֵךְ הַדֶּלֶת. אִם יָכוֹל הַדֶּלֶת לַעֲמֹד בִּפְנֵי עַצְמוֹ הַבַּיִת טָהוֹר. וְאִם לָאו הַבַּיִת טָמֵא לְפִי שֶׁנִּמְצָא הָאָדָם הוּא שֶׁחָצַץ בִּפְנֵי הַטֻּמְאָה וְהָאָדָם וְהַכֵּלִים מְבִיאִין וְאֵינָן חוֹצְצִין כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
3.
The following rules apply when the people carrying a corpse passed under an exedra, one of them closed the door to a house and locked it with a key so that the house would not become impure or if there was a person inside or outside who closed the door. If the door could stand close by itself, the house is pure. If not, the house is impure. The rationale is that in the latter situation, it was the person who intervened in the face of ritual impurity. As we explained, a person and keilim convey ritual impurity and do not intervene in the face of it.

הלכה ד
תַּנּוּר שֶׁהוּא עוֹמֵד בְּתוֹךְ הַבַּיִת וְעֵינוֹ קְמוּרָה לַחוּץ וְהֶאֱהִילוּ נוֹשְׂאֵי הַמֵּת עַל עֵינוֹ הַקְּמוּרָה הַתַּנּוּר טָמֵא וְהַבַּיִת טָהוֹר. שֶׁהֲרֵי אֵין הַתַּנּוּר גָּבוֹהַּ מֵעַל הָאָרֶץ כְּדֵי שֶׁיָּבִיא טֻמְאָה לַבַּיִת. מִגְדָּל הַבָּא בְּמִדָּה שֶׁהוּא עוֹמֵד בְּתוֹךְ הַפֶּתַח וְנִפְתַּח לַחוּץ טֻמְאָה בְּתוֹכוֹ הַבַּיִת טָהוֹר. טֻמְאָה בַּבַּיִת מַה שֶּׁבְּתוֹכוֹ טָמֵא שֶׁהֲרֵי הוּא פָּתוּחַ בְּתוֹךְ הַפֶּתַח וְדֶרֶךְ הַטֻּמְאָה לָצֵאת וְאֵין דַּרְכָּהּ לְהִכָּנֵס. הָיְתָה מוּכְנִי שֶׁלּוֹ מְשׁוּכָה לַאֲחוֹרָיו וְיוֹצֵאת פָּחוֹת מִטֶּפַח וְאֵינָהּ נִשְׁמֶטֶת וְטֻמְאָה שָׁם בְּתוֹכָהּ כְּנֶגֶד הַקּוֹרוֹת הַבַּיִת טָהוֹר שֶׁאַף עַל פִּי שֶׁהִיא יוֹצְאָה אֵינָהּ נִשְׁמֶטֶת וְאֵינָהּ יוֹצֵאת טֶפַח. וְהוּא שֶׁיִּהְיֶה בָּהּ טֶפַח עַל רוּם טֶפַח חָלוּל. אֲבָל אִם אֵין בַּמּוּכְנִי חֲלַל טֶפַח הֲרֵי הַטֻּמְאָה רְצוּצָה בְּתוֹךְ הַבַּיִת וְהַבַּיִת טָמֵא. הָיָה הַמִּגְדָּל עוֹמֵד בְּתוֹךְ הַבַּיִת וְהַטֻּמְאָה בְּתוֹכוֹ אוֹ בְּתוֹךְ הַתֵּבָה שֶׁלּוֹ אַף עַל פִּי שֶׁאֵין בִּיצִיאָתוֹ פּוֹתֵחַ טֶפַח הַבַּיִת טָמֵא. טֻמְאָה בַּבַּיִת מַה שֶּׁבְּתוֹכוֹ טָהוֹר שֶׁדֶּרֶךְ הַטֻּמְאָה לָצֵאת וְאֵין דַּרְכָּהּ לְהִכָּנֵס:
כסף משנה
4.
When an oven standing in a house has a dome-shaped opening that extends outside, if people carrying a corpse carried it over the opening that extends outside, the oven is impure, but the house is pure. The rationale is that the oven is not upraised above the ground so that it would bring impurity to the house.
When an oversized closet standing in an entrance opens to the outside and there is impurity in it, the house is pure. When there is impurity in the house, what is in the closet is impure, because it is open in the entrance and it is the nature of impurity to depart and not to enter. If its drawer was extended behind it, projecting less than a handbreadth, and could not be separated from the closet and there was impurity there opposite the boards of the roof of the house, the house is pure. The rationale is that even though it projects outward, it cannot be separated and it does not extend a handbreadth. This applies provided it is a handbreadth by a handbreadth and a handbreadth in height. If the drawer does not have an empty space of a handbreadth, the impurity is considered as flush within the house and the house is impure.
If the closet was standing in the house itself and there was impurity in it or in a chest within it, even though there is not an opening of a handbreadth through which the impurity could depart, the house is impure. If there is impurity in the house, everything in the closet is pure. The rationale is that the nature of impurity is to depart and not to enter.

הלכה ה
כֵּלִים שֶׁבֵּין הַמִּגְדָּל וּבֵין הָאָרֶץ שֶׁבֵּינוֹ וּבֵין הַכֹּתֶל וְשֶׁבֵּינוֹ וּבֵין הַקּוֹרוֹת אִם יֵשׁ שָׁם פּוֹתֵחַ טֶפַח טְמֵאִים וְאִם לָאו טְהוֹרִים שֶׁהֲרֵי אָנוּ רוֹאִים אֶת הַקּוֹרוֹת כְּאִלּוּ הֵן יוֹרְדוֹת וְסוֹתְמוֹת:
כסף משנה
5.
If there are keilim between the closet and the ground, between it and the wall, or between it and the ceiling, they are impure if there is a handbreadth of empty space there. If not, they are pure, because we considered it is if the beams of the ceiling descend and close the space between it and the closet.

הלכה ו
הָיְתָה טֻמְאָה תַּחַת הַמִּגְדָּל בֵּינוֹ וּבֵין הָאָרֶץ אוֹ בֵּינוֹ וּבֵין הַקּוֹרוֹת אוֹ בֵּינוֹ וּבֵין הַכֹּתֶל בֵּין שֶׁיֵּשׁ שָׁם חָלָל טֶפַח בֵּין שֶׁאֵין שָׁם הַבַּיִת טָמֵא. הָיָה עוֹמֵד בָּאֲוִיר וְטֻמְאָה בְּתוֹכוֹ כֵּלִים שֶׁבְּעָבְיוֹ טְהוֹרִים. טֻמְאָה בְּעָבְיוֹ כֵּלִים שֶׁבְּתוֹכוֹ טְהוֹרִים:
כסף משנה
6.
If there is impurity under the closet, between it and the earth, between it and the boards of the ceilings, or between it and the wall, the house is impure whether there is an open space of a handbreadth or not.
If the closet was standing under the open air and there was impurity in it, the keilim within the breadth of its walls are pure. If there is impurity within the breadth of its walls, the keilim inside of it are pure.

הלכה ז
כָּל שִׁפּוּעֵי אֹהָלִים כְּאֹהָלִים. כֵּיצַד. אֹהֶל שֶׁהוּא שׁוֹפֵעַ וְיוֹרֵד וְכָלֶה עַד כְּאֶצְבַּע וְטֻמְאָה בָּאֹהֶל כֵּלִים שֶׁתַּחַת הַשִּׁפּוּעַ טְמֵאִים. טֻמְאָה תַּחַת הַשִּׁפּוּעַ כֵּלִים שֶׁבָּאֹהֶל טְמֵאִים. הַטֻּמְאָה מִתּוֹךְ הַשִּׁפּוּעַ הַנּוֹגֵעַ בּוֹ מִתּוֹכוֹ טָמֵא טֻמְאַת שִׁבְעָה וְהַנּוֹגֵעַ בַּשִּׁפּוּעַ מֵאַחֲרָיו טָמֵא טֻמְאַת עֶרֶב, נַעֲשָׂה הַשִּׁפּוּעַ מֵאַחֲרָיו כְּאִלּוּ הוּא כְּלִי שֶׁנָּגַע בָּאֹהֶל. הָיְתָה הַטֻּמְאָה עַל אֲחוֹרֵי הַשִּׁפּוּעַ הַנּוֹגֵעַ בּוֹ מֵאֲחוֹרָיו טָמֵא טֻמְאַת שִׁבְעָה וְהַנּוֹגֵעַ בַּשִּׁפּוּעַ בְּתוֹכוֹ טָמֵא טֻמְאַת עֶרֶב. כַּחֲצִי זַיִת מִתּוֹכוֹ וְכַחֲצִי זַיִת מֵאֲחוֹרָיו הַנּוֹגֵעַ בּוֹ בֵּין מִתּוֹכוֹ בֵּין מֵאֲחוֹרָיו טָמֵא טֻמְאַת עֶרֶב. וְהָאֹהֶל עַצְמוֹ טָמֵא טֻמְאַת שִׁבְעָה:
כסף משנה
7.
All the slanted walls of tents are considered as the tents themselves.
What is implied? When a tent slants downward and ends within a fingerbreadth of the ground and there is impurity in the tent, the keilim under the slanted side are impure. If there is impurity under the slanted wall, the keilim in the tent are impure.
If there is impurity within the slanted wall, one who touches its inner side contracts impurity that lasts a week. One who touches its outer side contracts impurity that lasts until the evening, for the outer side of the slanting wall is considered as a k'li that touches a tent that has become impure.
If there is impurity on the outer side of the slanted wall, one who touches its outer side contracts impurity that lasts a week. One who touches the inner side of the slanting wall contracts impurity that lasts until the evening.
If there was half an olive-sized portion of a corpse inside the tent and half behind it, one who touches it - whether from inside or outside - contracts impurity that lasts until the evening. The tent itself contracts impurity that lasts for seven days.

הלכה ח
הָיָה כְּנַף הָאֹהֶל מְרֻדָּד עַל הָאָרֶץ וְטֻמְאָה תַּחַת כְּנַף הָאֹהֶל הַפָּרוּשׂ עַל הָאָרֶץ אוֹ עַל גַּבֵּי הַכָּנָף. טֻמְאָה בּוֹקַעַת וְעוֹלָה בּוֹקַעַת וְיוֹרֶדֶת:
כסף משנה
8.
If the edges of the tent were spread out on the ground and there was impurity on the ground under an edge of the tent spread out or above it, the impurity pierces through and ascends, pierces through and descends.

טהרה הלכות טומאת מת פרק יח
Taharah Tumas Meis Chapter 18