כֹּתֶל חָצֵר הַמַּבְדִּיל בֵּין שְׁנֵי שֻׁתָּפִין שֶׁנָּפַל. יֵשׁ לְכָל אֶחָד מִשְּׁנֵיהֶם לָכֹף עַל חֲבֵרוֹ לִבְנוֹתוֹ עַד גֹּבַהּ אַרְבַּע אַמּוֹת כְּדֵי שֶׁלֹּא יִרְאוּ זֶה אֶת זֶה. אֲבָל יֶתֶר עַל אַרְבַּע אַמּוֹת אֵין מְחַיְּבִין אוֹתוֹ. רָצָה הָאֶחָד וְהִגְבִּיהַּ הַכֹּתֶל יוֹתֵר עַל אַרְבַּע אַמּוֹת. אִם בָּא חֲבֵרוֹ וּבָנָה כֹּתֶל אַחֵר גָּבוֹהַּ כְּנֶגֶד הַכֹּתֶל שֶׁבֵּינֵיהֶן מְחַיְּבִין אוֹתוֹ לִתֵּן חֶלְקוֹ בַּגֹּבַהּ שֶׁכְּנֶגֶד כָּתְלוֹ. כֵּיצַד. בָּנָה אֶחָד כֹּתֶל שֶׁבֵּינֵיהֶן וְהִגְבִּיהוֹ עֶשֶׂר אַמּוֹת וּבָא חֲבֵרוֹ וּבָנָה כֹּתֶל אַחֵר כְּנֶגְדּוֹ אוֹ בְּצִדּוֹ לַעֲשׂוֹת לוֹ בַּיִת וְהִגְבִּיהַּ הַכֹּתֶל הָאַחֵר שֵׁשׁ אַמּוֹת מְחַיְּבִין אוֹתוֹ לִתֵּן חֶלְקוֹ בִּשְׁתֵּי אַמּוֹת שֶׁמּוֹסִיף עַל אַרְבַּע אַמּוֹת שֶׁהֲרֵי נִרְאֶה מִמַּעֲשָׂיו שֶׁהוּא רוֹצֶה בָּהֶן. וְכֵן אִם חָקַק בְּרֹאשׁ הַכֹּתֶל שֶׁבֵּינֵיהֶן מָקוֹם לְהַנִּיחַ בּוֹ הַקּוֹרוֹת אוֹ שֶׁבָּנָה עָלָיו קוֹרָה גְּדוֹלָה שֶׁהַקּוֹרוֹת נִשְׁעָנִין עָלֶיהָ מְחַיְּבִין אוֹתוֹ לִתֵּן חֶלְקוֹ בְּשֵׁשׁ הָאַמּוֹת כֻּלָּן שֶׁהוֹסִיף חֲבֵרוֹ עַל הָאַרְבַּע אַמּוֹת אַף עַל פִּי שֶׁלֹּא בָּנָה כָּל הַכֹּתֶל שֶׁהֲרֵי גִּלָּה דַּעְתּוֹ שֶׁהוּא רוֹצֶה בְּכָל הַגֹּבַהּ הַזֶּה:
When a wall that separates between two partners falls, each of the partners may compel the other to share in its construction until it reaches the height of four cubits, so that they will not see each other. We do not, however, compel a partner to build it any higher than four cubits. The following rule applies if one of the partners takes the initiative and builds the wall higher than four cubits. If the other colleague comes and builds another wall of his as high as the wall between them, we obligate that partner to pay his share in the additional height that is opposite his wall. What is implied? One person built a wall between himself and another partner and elevated it to a height of ten cubits. Afterwards, the other partner came and built another wall opposite it or at its side for the sake of making a room, and built that wall six cubits high. We obligate him to pay his share in the two cubits that were added to the minimum of four cubits. For it is obvious that he desired them. Similarly, if he hewed out a place on the top of the wall between them to place beams or affixed permanently there a large beam on which the others rest, we obligate him to pay his share in the entire six cubits that his colleague added to the minimum of four cubits, although he did not build the entire wall. For he revealed his intent, that he desired the entire height of the wall.
