"Upon the houses in which they shall eat it" (Exodus 12:7). I know only houses in which they eat it; from where do I include houses in which they sleep? Scripture teaches, "upon the houses where you are" (Exodus 12:13) -- in any case. It is taught: "upon the houses in which they shall eat it" teaches that the Passover may be eaten by two companies. One might think that an eater may eat in two places; Scripture teaches, "in one house it shall be eaten" (Exodus 12:46). From here they said: a servant who ate an olive's bulk beside the oven -- if he is clever, he fills his belly from it. If the members of the company wish to do him a kindness, they come and sit beside him; these are the words of Rabbi Yehudah. Rabbi Shimon says: "the houses in which they shall eat it" teaches that an eater may eat in two places. One might think it may be eaten by two companies; Scripture teaches, "in one house it shall be eaten." This master holds that the way the text is read is authoritative, and that master holds that the traditional spelling is authoritative.
Eating the Passover in One House and One Company
Yalkut Shimoni on Torah 197:2
עַל הַבָּתִּים אֲשֶׁר יֹאכְלוּ אֹתוֹ בָּהֶם. אֵין לִי אֶלָּא בָּתִּים שֶׁהָיוּ אוֹכְלִין אוֹתוֹ בָּהֶן, בָּתִּים שֶׁהָיוּ יְשֵׁנִים בָּהֶן מִנַּיִן, תַּלְמוּד לוֹמַר (להלן פסוק יג) עַל הַבָּתִּים אֲשֶׁר אַתֶּם שָׁם, מִכָּל מָקוֹם. תַּנְיָא, עַל הַבָּתִּים אֲשֶׁר יֹאכְלוּ אֹתוֹ בָּהֶם, מְלַמֵּד שֶׁהַפֶּסַח נֶאֱכָל בִּשְׁתֵּי חֲבוּרוֹת, יָכוֹל שֶׁהָאוֹכֵל אוֹכֵל בִּשְנֵי מְקוֹמוֹת, תַּלְמוּד לוֹמַר "בְּבַיִת אֶחָד יֵאָכֵל", מִכָּאן אָמְרוּ, הַשַּׁמָּשׁ שֶׁאָכַל כְּזַיִת בְּצַד הַתַּנּוּר אִם פִּקֵּחַ מְמַלֵּא כְּרֵסוֹ הֵימֶנּוּ רָצוּ בְּנֵי חֲבוּרָה לַעֲשׂוֹת עִמּוֹ טוֹבָה בָּאִין וְיוֹשְׁבִין בְּצִדּוֹ, דִּבְרֵי רַבִּי יְהוּדָה. רַבִּי שִׁמְעוֹן אוֹמֵר, בָּתִּים אֲשֶׁר יֹאכְלוּ אֹתוֹ, מְלַמֵּד שֶׁהָאוֹכֵל אוֹכֵל בִּשְׁנֵי מְקוֹמוֹת יָכוֹל יְהֵא נֶאֱכָל בִּשְׁתֵּי חֲבוּרוֹת, תַּלְמוּד לוֹמַר "בְּבַיִת אֶחָד יֵאָכֵל", מַר סָבַר יֵשׁ אֵם לַמִּקְרָא וּמַר סָבַר יֵשׁ אֵם לַמָּסֹרֶת.