What lit Noah's ark through a year of darkness
The sages debate the meaning of the tzohar (bright item) Noah was commanded to place in the ark, with Rabbi Abba bar Kahana identifying it as a window and Rabbi Levi as a luminous precious stone that signaled day and night by its dimness or brightness. Further detail is given regarding the ark's internal structure—its many compartments, the tapering upper cubit, and its three stories divided among refuse, the pure animals with Noah and his sons, and the impure animals—while Rabbi Yitzḥak derives from the side-placed entrance a practical halachah (law) that a large room's doorway should be set to the side rather than the center. The passage closes by noting that the word taaseha ("you shall craft it") implies that the ark itself participated in its own construction.AI summary · anthropic/claude-sonnet-5
“You shall make a bright item for the ark, and to a cubit you shall complete it at the top, and the entrance of the ark you shall place at its side; with lower, second-level, and third stories you shall craft it” (Genesis 6:15). “You shall make a bright item [tzohar] for the ark” – Rabbi Ḥunya, Rabbi Pinḥas, Rabbi Ḥanin, and Rabbi Hoshaya did not disagree about this. Rabbi Abba bar Kahana and Rabbi Levi did disagree. Rabbi Abba bar Kahana said: It was a window. Rabbi Levi said: It was a [luminous] precious stone.
Rabbi Pinḥas said in the name of Rabbi Levi: All twelve months that Noah was in the ark, he needed neither the light of the sun during the day nor the light of the moon at night; rather, he had a precious stone that he had suspended. When it was dim he knew that it was day, and when it shined brightly he knew that it was night.
Rabbi Huna said: We were once fleeing from enemy troops in a cave in Tiberias, and we had lamps with us. When they were dim, we knew that it was day, and when they shined brightly, we knew that it was night. “And to a cubit you shall complete it at the top” – Rabbi Yehuda and Rabbi Neḥemya, Rabbi Yehuda says: There were three hundred and sixty compartments in it [the ark], each one ten cubits by ten cubits, and two four-cubit aisles with chambers on one side and the other side, and again chambers on one side and the other side, and two cubits [for two additional aisles] on either side. Rabbi Neḥemya said: There were nine hundred compartments in it, each compartment being six cubits by six cubits, and three aisles, each four cubits, with chambers on one side and on the other side, and two cubits [for two additional aisles] on each of the sides. According to the opinion of Rabbi Yehuda it is difficult and according to the opinion of Rabbi Neḥemya it is difficult.
Rabbi Yehuda and Rabbi Neḥemya, Rabbi Yehuda says: Like the cubit below, so was the cubit above – “and by the cubit you shall complete it at the top.” Rabbi Neḥemya said: It was [built] like a kind of vault continuously inclining as it ascended, until it reached its single cubit, as it is stated: “and to a cubit…” “And the entrance of the ark you shall place at its side” – Rabbi Yitzḥak said: The Torah gives you instruction about practical matters: If a person builds a large room that is ten by ten cubits [or more], one should place its doorway entrance off to the side.
“Lower, second-level, and third stories you shall craft it” – the lower ones [compartments] were for refuse, the second-level ones were for him, his sons and the pure animals, and the upper ones were for the impure animals. Some exchange this: The lower ones were for the impure animals, the second-level ones for him, his sons and the pure animals, and the upper ones for the refuse. How would he do this? There was a partitioned opening and he would sweep it to the side.
“You shall craft it [taaseha]” – it [the ark], too, assisted [in building] itself.
צֹהַר תַּעֲשֶׂה לַתֵּבָה (בראשית ו, טז), רַבִּי חוּנְיָה וְרַבִּי פִּינְחָס רַבִּי חָנִין וְרַבִּי הוֹשַׁעְיָא לָא מְפָרְשִׁין, רַבִּי אַבָּא בַּר כַּהֲנָא וְרַבִּי לֵוִי מְפָרְשִׁין. רַבִּי אַבָּא בַּר כַּהֲנָא אָמַר, חַלּוֹן. רַבִּי לֵוִי אָמַר, מַרְגָּלִיּוֹת. רַבִּי פִּינְחָס מִשּׁוּם רַבִּי לֵוִי אָמַר כָּל שְׁנֵים עָשָׂר חֹדֶשׁ שֶׁהָיָה נֹחַ בַּתֵּבָה, לֹא צָרִיךְ לֹא לְאוֹר הַחַמָּה בַּיּוֹם וְלֹא לְאוֹר הַלְּבָנָה בַּלַּיְלָה, אֶלָּא מַרְגָּלִית הָיְתָה לוֹ וְהָיָה תּוֹלֶה אוֹתָהּ, וּבְשָׁעָה שֶׁהִיא כֵּהָה הָיָה יוֹדֵעַ שֶׁהוּא יוֹם, וּבְשָׁעָה שֶׁהָיְתָה מַבְהֶקֶת הָיָה יוֹדֵעַ שֶׁהוּא לַיְלָה. אָמַר רַבִּי הוּנָא עֲרִיקִין הֲוֵינָן מִן קוֹמֵי גוּנְדָא בַּהֲדָא בּוּטִיטָה דִּטְבֶרְיָה וְהָיָה בְּיָדֵינוּ נֵרוֹת, בְּשָׁעָה שֶׁהָיוּ כֵּהִים הָיִינוּ יוֹדְעִים שֶׁהוּא יוֹם, וּבְשָׁעָה שֶׁהָיוּ מַבְהִיקִים הָיִינוּ יוֹדְעִים שֶׁהוּא לָיְלָה. (בראשית ו, טז): וְאֶל אַמָּה תְּכַלֶּנָּה מִלְּמַעְלָה, רַבִּי יְהוּדָה וְרַבִּי נְחֶמְיָה, רַבִּי יְהוּדָה אוֹמֵר שְׁלשׁ מֵאוֹת וְשִׁשִּׁים קִילִין הָיוּ בָהּ, עֶשֶׂר אַמּוֹת עַל עֶשֶׂר אַמּוֹת, וּשְׁתֵּי פְּלָטִיּוֹת שֶׁל אַרְבַּע אַמּוֹת, קִילִין מִיכָּן וְקִילִין מִיכָּן, וְקִילִין מִיכָּן וְקִילִין מִיכָּן, וּשְׁנֵי אַמּוֹת לַצְּדָדִים. רַבִּי נְחֶמְיָה אָמַר תְּשַׁע מֵאוֹת קִילִין הָיוּ בָהּ, וְקִיל שֵׁשׁ אַמּוֹת עַל שֵׁשׁ אַמּוֹת. וְשָׁלשׁ פְּלָטִיּוֹת שֶׁל אַרְבַּע אַרְבַּע, וְקִיל מִיכָּן וְקִיל מִיכָּן וּשְׁתֵּי אַמּוֹת לַצְּדָדִין. עַל דַּעְתֵּיהּ דְּרַבִּי יְהוּדָה לָא נִיחָא, וְעַל דַּעְתֵּיהּ דְּרַבִּי נְחֶמְיָה לָא נִיחָא. רַבִּי יְהוּדָה וְרַבִּי נְחֶמְיָה, רַבִּי יְהוּדָה אוֹמֵר כְּאַמָּתָה מִלְמַטָּה כָּךְ אַמָּתָה מִלְּמַעְלָה, וְאֶל אַמָּה תְּכַלֶּנָּה מִלְּמַעְלָה. רַבִּי נְחֶמְיָה אָמַר כְּמִין קוֹמָרוֹטוֹן הָיְתָה וְהָיָה מַשְׁקִיף בָּהּ וְעוֹלֶה וּמַשְׁקִיף בָּהּ וְעוֹלֶה, עַד שֶׁהֶעֱמִידָהּ עַל אַמָּתָה, שֶׁנֶּאֱמַר: וְאֶל אַמָּה וגו'. וּפֶתַח הַתֵּבָה בְּצִדָּהּ תָּשִׂים, אָמַר רַבִּי יִצְחָק לִמְדָתְךָ תּוֹרָה דֶּרֶךְ אֶרֶץ, שֶׁאִם עוֹשֶׂה אָדָם טְרַקְלִין עֶשֶׂר עַל עֶשֶׂר, יְהֵא עוֹשֶׂה פִּתְחוֹ מִן הַצַּד. תַּחְתִּיִּם שְׁנִיִּם וּשְׁלִשִׁים תַּעֲשֶׂהָ, תַּחְתִּיִּם לִזְבָלִים, שְׁנִיִּם לוֹ וּלְבָנָיו וְלַטְּהוֹרִים, וְהָעֶלְיוֹנִים לַטְּמֵאִים. וְיֵשׁ מַחֲלִיפִין תַּחְתִּיִּם לַטְּמֵאִים, שְׁנִיִּם לוֹ וּלְבָנָיו וְלַטְּהוֹרִים, וְהָעֶלְיוֹנִים לִזְבָלִים. כֵּיצַד הָיָה עוֹשֶׂה אֶלָּא כְּמִין קָטָרַקְטִין הָיָה לוֹ פּוֹסְסָן מִן הַצַּד. תַּעֲשֶׂהָ, אַף הִיא הָיְתָה מְסַיַּעַת אֶת עַצְמָהּ.