8:4ח׳:ד׳
1 א

בחדש השביעי. סִיוָן, וְהוּא שְׁבִיעִי לְכִסְלֵו שֶׁבּוֹ פָּסְקוּ הַגְּשָׁמִים:

בחדש השביעי IN THE SEVENTH MONTH — viz., Sivan, which is the seventh from Kislev in which the rains stopped falling.

2 ב

בשבעה עשר יום. מִכָּאן אַתָּה לָמֵד שֶׁהָיְתָה הַתֵּבָה מְשֻׁקַּעַת בַּמַּיִם י"א אַמָּה, שֶׁהֲרֵי כְתִיב בָּעֲשִׂירִי בְּאֶחָד לַחֹדֶשׁ נִרְאוּ רָאשֵׁי הֶהָרִים, זֶה אָב, שֶׁהִיא עֲשִׂירִי לְמַרְחֶשְׁוָן לִירִידַת גְּשָׁמִים, וְהֵם הָיוּ גְבוֹהִים עַל הֶהָרִים חֲמֵשׁ עֶשְׂרֵה אַמָּה, וְחָסְרוּ מִיּוֹם אֶחָד בְּסִיוָן עַד אֶחָד בְּאָב חֲמֵשׁ עֶשְׂרֵה אַמָּה לְשִּׁשִּׁים יוֹם, הֲרֵי אַמָּה לְד' יָמִים, נִמְצָא, שֶׁבְּי"ו בְּסִיוָן לֹא חָסְרוּ אֶלָּא ד' אַמּוֹת וְנָחָה הַתֵּבָה לְיוֹם הַמָּחֳרָת; לָמַדְתָּ, שֶׁהָיְתָה מְשֻׁקַּעַת י"א אַמָּה בַמַּיִם שֶׁעַל רָאשֵׁי הֶהָרִים:

בשבעה עשר יום ON THE SEVENTEENTH DAY — From here you may infer that the Ark was submerged in the water to a depth of eleven cubits. For it is written (next verse) “In the tenth month on the first day of the month the tops of the mountains were seen” and this was Ab which is the tenth month after Cheshvan — after the rain began to fall. Now the waters were 15 cubits high above the mountains so that they subsided from the first of Sivan to the first of Ab 15 cubits for those 60 intervening days, which is one cubit each four days. Consequently by the sixteenth of Sivan they had subsided only 4 cubits, and since the Ark rested on Ararat on the next day, you may learn that it was submerged eleven cubits in the waters which were then still above the mountain tops (Genesis Rabbah 33:7).