I'm wondering what explanations are offered (preferably by the various Rishonim), if any, as to why we read Lv. 22:26-32 on the first day of Sukkot. The latter part of the reading (23:1 and on) is easier to understand as it deals directly with the festivals. But the opening piece doesn't, discussing the details of minimum age and some other requirements for sacrifices.
וַיְדַבֵּר יְהוָה, אֶל-מֹשֶׁה לֵּאמֹר. שׁוֹר אוֹ-כֶשֶׂב אוֹ-עֵז כִּי יִוָּלֵד, וְהָיָה שִׁבְעַת יָמִים תַּחַת אִמּוֹ; וּמִיּוֹם הַשְּׁמִינִי, וָהָלְאָה, יֵרָצֶה, לְקָרְבַּן אִשֶּׁה לַיהוָה. וְשׁוֹר, אוֹ-שֶׂה--אֹתוֹ וְאֶת-בְּנוֹ, לֹא תִשְׁחֲטוּ בְּיוֹם אֶחָד. וְכִי-תִזְבְּחוּ זֶבַח-תּוֹדָה, לַיהוָה--לִרְצֹנְכֶם, תִּזְבָּחוּ. בַּיּוֹם הַהוּא יֵאָכֵל, לֹא-תוֹתִירוּ מִמֶּנּוּ עַד-בֹּקֶר: אֲנִי, יְהוָה. וּשְׁמַרְתֶּם, מִצְוֺתַי, וַעֲשִׂיתֶם, אֹתָם: אֲנִי, יְהוָה. וְלֹא תְחַלְּלוּ, אֶת-שֵׁם קָדְשִׁי, וְנִקְדַּשְׁתִּי, בְּתוֹךְ בְּנֵי יִשְׂרָאֵל: אֲנִי יְהוָה, מְקַדִּשְׁכֶם. לג הַמּוֹצִיא אֶתְכֶם מֵאֶרֶץ מִצְרַיִם, לִהְיוֹת לָכֶם לֵאלֹהִים: אֲנִי, יְהוָה.
And the LORD spoke unto Moses, saying: When a bullock, or a sheep, or a goat, is brought forth, then it shall be seven days under the dam; but from the eighth day and thenceforth it may be accepted for an offering made by fire unto the LORD. And whether it be cow or ewe, ye shall not kill it and its young both in one day. And when ye sacrifice a sacrifice of thanksgiving unto the LORD, ye shall sacrifice it that ye may be accepted. On the same day it shall be eaten; ye shall leave none of it until the morning: I am the LORD. And ye shall keep My commandments, and do them: I am the LORD. And ye shall not profane My holy name; but I will be hallowed among the children of Israel: I am the LORD who hallow you, that brought you out of the land of Egypt, to be your God: I am the LORD.
What is the relevance to Sukkot? Do the Rishonim offer any explanations as to the relevance of this to Sukkot?