Reference for Sukkah 2:9
כָּל שִׁבְעַת הַיָּמִים אָדָם עוֹשֶׂה סֻכָּתוֹ קֶבַע וּבֵיתוֹ עֲרַאי. יָרְדוּ גְשָׁמִים, מֵאֵימָתַי מֻתָּר לְפַנּוֹת, מִשֶּׁתִּסְרַח הַמִּקְפָּה. מָשְׁלוּ מָשָׁל, לְמָה הַדָּבָר דּוֹמֶה, לְעֶבֶד שֶׁבָּא לִמְזוֹג כּוֹס לְרַבּוֹ, וְשָׁפַךְ לוֹ קִיתוֹן עַל פָּנָיו:
All seven days (of the festival), one makes his succah permanent and his house temporary, [e.g., If he has beautiful vessels and spreads, he brings them into the succah.] If it rains, when is it permitted to leave (the succah)? When the mikpeh gets spoiled. [Any dish which is neither soft nor hard but stiff (kafui) is called "mikpeh." Most men shun such food, which with (the addition of) a little water is entirely spoiled. And a mikpeh of pounded beans spoils more quickly in a rain than other mikpoth. If there were enough rain to spoil a mikpeh of this kind (were it there), he may leave immediately.] They offered an analogy for this. To what may this be compared? A servant comes to pour a cup (of wine) for his master, and he [the master] dashes the (contents of the) jug in his face, [this, by way of saying: "I do not want your service!" Here, too, the rain shows that the Master is not favorably disposed to His servants' deeds.]