"If you build a new house, you shall make a railing for your roof": This tells me only of "building." Whence do I derive (the same for) acquiring, inheriting, and receiving as a gift? From (Ibid.) "and you shall not place blood in your house" — in any event.
In that case I might think (that also included) is the building of a gateway, a portico, or a porch; it is, therefore, written "a house." Just as a "house" is characterized by being subject to occupancy (so, all that are similarly characterized are subsumed in the halachah) — to exclude the aforementioned, which are not thus characterized.
"you shall make a railing for your roof": This tells me only of a roof. Whence do I derive the same (i.e., the need for protective safeguards) for holes, pits, caves, and ditches? From "and you shall not place blood in your house" (i.e., in the domain of your house. If so, why is "roof" mentioned? To exclude a ramp (and the like).
"a new house": Rebbi says: From the time of its "newness" (i.e., even before it is inhabited), make a railing for it. "a house": to exclude an ulam (an entrance hall). How (high a railing is required for) a place (where one keeps) his rolling machine? Three hand-breadths. For the part used for walking about? Ten hand-breadths.
(Ibid.) "when the faller falls from it": He was destined to fall from the six days of creation, but "merit is channeled (via the Heavenly ordinance) through the meritorious, and guilt through the guilty" (so that he who is guilty of not building the railing bears the guilt of the fall).
"when the faller falls from it": "from it," and not within it. (How so?) If the public thoroughfare were ten hand-breadths above his roof, (and he fell from there upon it, the owner of the house is) not liable, it being written "from it (the roof), and not within it.
R. Yishmael says: Scripture comes to teach you how he is judged, viz. (Koheleth 9:12) "For a man does not know his time, like fishes that are caught in a flimsy net and like birds that are caught in the snare. Like them men are snared in a time of evil (i.e., when their evil is visited upon them), when it falls upon them suddenly."
A house which is not four by four hand-breadths (because it is not considered "a house") is exempt from a railing, a mezuzah and an eruv (a halachic device of "amalgamation" for Sabbaths and festivals); and it is not made an ibbur (an "outskirt") of a city (for purposes of such amalgamation), and it does not render food tevel (untithed) for purposes of tithing, and it is not allocated four ells (in a courtyard.) If one makes a vow (not to benefit) from a house, he may sit in it, and it is not subject to plague-spot uncleanliness, and it is not irredeemably sold vis-à-vis the Jubilee year, and he is not returned to from the battlefield (viz. Devarim 20:5).
(דברים כב ח) כִּי תִבְנֶה בַּיִת חָדָשׁ, אֵין לִי אֶלָּא בּוֹנֶה. לָקַח, יָרַשׁ, וְנִתַּן לוֹ בְּמַתָּנָה מִנַּיִן? תַּלְמוּד לוֹמַר: בַּיִת, מִכָּל מָקוֹם.
"If you build a new house, you shall make a railing for your roof": This tells me only of "building." Whence do I derive (the same for) acquiring, inheriting, and receiving as a gift? From (Ibid.) "and you shall not place blood in your house" — in any event.
לֹא תָשִׂים דָּמִים בְּבֵיתֶךָ, אֵין לִי אֶלָּא בַּיִת. מִנַּיִן לְבוֹנֶה בֵּית הַתֶּבֶן, בֵּית הַבָּקָר, בֵּית הָעֵצִים, בֵּית הָאוֹצָרוֹת? תַּלְמוּד לוֹמַר: וְלֹא תָשִׂים דָּמִים בְּבֵיתֶךָ.
"a house": This tells me only of a house. Whence do I derive (the same for) a straw-bin, a cattle-shed, and a store-house? From "If you build."
יָכוֹל אַף הַבּוֹנֶה בֵּית שַׁעַר אַכְסַדְרָה וּמִרְפֶּסֶת? תַּלְמוּד לוֹמַר: בַּיִת, מָה בַּיִת מְיֻחָד, שֶׁהוּא בֵּית דִּירָה – יָצְאוּ אֵלּוּ, שֶׁאֵינָם בֵּית דִּירָה.
In that case I might think (that also included) is the building of a gateway, a portico, or a porch; it is, therefore, written "a house." Just as a "house" is characterized by being subject to occupancy (so, all that are similarly characterized are subsumed in the halachah) — to exclude the aforementioned, which are not thus characterized.
וְעָשִׂיתָ מַעֲקֶה לְגַגֶּךָ, אֵין לִי אֶלָּא גַּג. מִנַּיִן לְרַבּוֹת בּוֹרוֹת, שִׁיחִים, וּמְעָרוֹת, חֲרִיצִים וּנְעִיצִים? תַּלְמוּד לוֹמַר: וְלֹא תָשִׂים דָּמִים בְּבֵיתֶךָ. אִם כֵּן לָמָּה נֶאֱמַר גַּג? פְּרָט לְכֶבֶשׁ. בַּיִת – לְרַבּוֹת הֵיכָל. גַּג – פְּרָט לָאוּלָם.
"you shall make a railing for your roof": This tells me only of a roof. Whence do I derive the same (i.e., the need for protective safeguards) for holes, pits, caves, and ditches? From "and you shall not place blood in your house" (i.e., in the domain of your house. If so, why is "roof" mentioned? To exclude a ramp (and the like).
חָדָשׁ, רַבִּי אוֹמֵר: מִשְּׁעַת חִדּוּשׁוֹ עֲשֵׂה לוֹ מַעֲקֶה. כַּמָּה הוּא מַעֲקֶה? מַעְגִּילוֹ שְׁלֹשָׁה טְפָחִים, בֵּית דָּרְסוֹ עֲשָׂרָה.
"a new house": Rebbi says: From the time of its "newness" (i.e., even before it is inhabited), make a railing for it. "a house": to exclude an ulam (an entrance hall). How (high a railing is required for) a place (where one keeps) his rolling machine? Three hand-breadths. For the part used for walking about? Ten hand-breadths.
וְעָשִׂיתָ מַעֲקֶה לְגַגֶּךָ – מִצְוַת עֲשֵׂה. וְלֹא תָשִׂים דָּמִים בְּבֵיתֶךָ – מִצְוַת לֹא תַעֲשֶׂה.
"you shall make a railing for your roof": a positive commandment. "and you shall not place blood in your house": a negative commandment.
כִּי יִפֹּל הַנֹּפֵל מִמֶּנּוּ, רָאוּי זֶה שֶׁיִּפּוֹל! אֶלָּא מְגַלְגְּלִים זְכוּת עַל יְדֵי זַכַּי וְחוֹבָה עַל יְדֵי חַיָּב.
(Ibid.) "when the faller falls from it": He was destined to fall from the six days of creation, but "merit is channeled (via the Heavenly ordinance) through the meritorious, and guilt through the guilty" (so that he who is guilty of not building the railing bears the guilt of the fall).
מִמֶּנּוּ – וְלֹא לְתוֹכוֹ; שֶׁאִם הָיָה רְשׁוּת הָרַבִּים גָּבוֹהַּ מִמֶּנּוּ עֲשָׂרָה טְפָחִים וְנָפַל מִמֶּנּוּ לְתוֹכוֹ – פָּטוּר, שֶׁנֶּאֱמַר: מִמֶּנּוּ וְלֹא לְתוֹכוֹ.
"when the faller falls from it": "from it," and not within it. (How so?) If the public thoroughfare were ten hand-breadths above his roof, (and he fell from there upon it, the owner of the house is) not liable, it being written "from it (the roof), and not within it.
דָּבָר אַחֵר: כִּי תִבְנֶה, רַבִּי יִשְׁמָעֵאל אוֹמֵר: בָּא הַכָּתוּב לְלַמֶּדְךָ שֶׁאֵין אָדָם יוֹדֵעַ כֵּיצַד הוּא נִדּוֹן, שֶׁנֶּאֱמַר (קהלת ט יב): ״כִּי לֹא יֵדַע הָאָדָם אֶת עִתּוֹ, כַּדָּגִים שֶׁנֶּאֱחָזִים בִּמְצוֹדָה״.
R. Yishmael says: Scripture comes to teach you how he is judged, viz. (Koheleth 9:12) "For a man does not know his time, like fishes that are caught in a flimsy net and like birds that are caught in the snare. Like them men are snared in a time of evil (i.e., when their evil is visited upon them), when it falls upon them suddenly."
בַּיִת מִכָּן אָמְרוּ: בַּיִת שֶׁאֵין בּוֹ אַרְבַּע עַל אַרְבַּע – פָּטוּר מִן הַמַּעֲקֶה וּמִן הַמְּזוּזָה וּמִן הָעֵרוּב, וְאֵין עוֹשִׂים אוֹתוֹ עִבּוּר לָעִיר, וְלֹא טִבּוּל לַמַּעַשְׂרוֹת, וְאֵין נוֹתְנִים לוֹ אַרְבַּע אַמּוֹת לְפִתְחוֹ; הַנּוֹדֵר מִן הַבַּיִת מֻתָּר לֵישֵׁב בּוֹ; וְאֵין מִטַּמֵּא בִּנְגָעִים, וְאֵין צָמִית בַּיּוֹבֵל, וְאֵין חוֹזְרִים עָלָיו מֵעֶרְכֵי הַמִּלְחָמָה.
A house which is not four by four hand-breadths (because it is not considered "a house") is exempt from a railing, a mezuzah and an eruv (a halachic device of "amalgamation" for Sabbaths and festivals); and it is not made an ibbur (an "outskirt") of a city (for purposes of such amalgamation), and it does not render food tevel (untithed) for purposes of tithing, and it is not allocated four ells (in a courtyard.) If one makes a vow (not to benefit) from a house, he may sit in it, and it is not subject to plague-spot uncleanliness, and it is not irredeemably sold vis-à-vis the Jubilee year, and he is not returned to from the battlefield (viz. Devarim 20:5).