Mishnayos Sukkah Perek 2 Mishnah 6

Rabbi Eliezer says: A person is obligated to eat fourteen meals in the sukka over the course of the seven days of the festival of Sukkot, one during the day each day and one at night each night. And the Rabbis say: There is no quota for the number of meals, and one may choose whether or not to eat any of the meals except for the meal on the evening of the first Festival day of Sukkot, which one is required to eat in the sukka. And furthermore, Rabbi Eliezer said: One who did not eat a meal on the evening of the first day of the Festival should compensate with a meal on the evening of the last day of the Festival, on the Eighth Day of Assembly, despite the fact that he will not eat it in the sukka. And the Rabbis say: There is no compensation for this matter, and with regard to similar cases where it is impossible to rectify failure to fulfill a positive mitzva, it is stated: “That which is crooked cannot be made straight; and that which is wanting cannot be numbered” (Ecclesiastes 1:15).

רַבִּי אֱלִיעֶזֶר אוֹמֵר, אַרְבַּע עֶשְׂרֵה סְעוּדוֹת חַיָּב אָדָם לֶאֱכֹל בַּסֻּכָּה, אַחַת בַּיּוֹם וְאַחַת בַּלָּיְלָה. וַחֲכָמִים אוֹמְרִים, אֵין לַדָּבָר קִצְבָה, חוּץ מִלֵּילֵי יוֹם טוֹב רִאשׁוֹן שֶׁל חָג בִּלְבָד. וְעוֹד אָמַר רַבִּי אֱלִיעֶזֶר, מִי שֶׁלֹּא אָכַל לֵילֵי יוֹם טוֹב הָרִאשׁוֹן, יַשְׁלִים בְּלֵילֵי יוֹם טוֹב הָאַחֲרוֹן. וַחֲכָמִים אוֹמְרִים, אֵין לַדָּבָר תַּשְׁלוּמִין, עַל זֶה נֶאֱמַר (קהלת א) מְעֻוָּת לֹא יוּכַל לִתְקֹן, וְחֶסְרוֹן לֹא יוּכַל לְהִמָּנוֹת: