סימן קג סעיף ב
אֵיזֶהוּ כִּבּוּד. זֶה שֶׁאָמְרוּ רַבּוֹתֵינוּ זִכְרוֹנָם לִבְרָכָה, שֶׁמִּצְוָה עַל הָאָדָם לְגַלֵּחַ בְּעֶרֶב יוֹם טוֹב, כְּדֵי שֶׁלֹּא יִכָּנֵס לָרֶגֶל כְּשֶׁהוּא מְנֻוָּל. וְכֵן מִצְוָה לִרְחוֹץ בְּחַמִּין וְלָחֹף רֹאשׁוֹ וְלִטּוֹל צִפָּרְנָיו בְּעֶרֶב יוֹם טוֹב, כְּמוֹ בְּעֶרֶב שַׁבָּת. וְכֵן מִצְוָה לָלוּשׁ פַּת בְּבֵיתוֹ בְּעֶרֶב יוֹם טוֹב לִכְבוֹד יוֹם טוֹב כְּמוֹ בְּעֶרֶב שַׁבָּת. וְכֵן אָסוּר לֶאֱכוֹל בְּעֶרֶב יוֹם טוֹב מִן הַמִּנְחָה וּלְמַעְלָה כְּמוֹ בְּעֶרֶב שַׁבָּת, כְּדֵי שֶׁיֹּאכַל סְעוּדַּת יוֹם טוֹב לְתֵאָבוֹן. וְאִם חָל עֶרֶב יוֹם טוֹב בַּשַׁבָּת, יֹאכַל סְעוּדָּה שְׁלִישִׁית קֹדֶם מִנְחָה קְטַנָּה. וְכֵן הַדִּין בְּיוֹם טוֹב רִאשׁוֹן שֶׁהוּא עֶרֶב יוֹם טוֹב שֵׁנִי.
What is meant by honor? As our Rabbis, of blessed memory, said, "It is a mitzvah for a man to take a haircut on erev Yom Tov so that he does not enter the festival looking untidy. It is also a mitzvah to bathe in warm water, to wash your hair, and to cut your nails on erev Yom Tov, the same as on erev Shabbos. It is also a mitzvah to bake challos in your house on erev Yom Tov in honor of Yom Tov, just as it is on erev Shabbos. It is forbidden to3Ramah 529:1. The term forbidden is not to be taken literally, for it is not forbidden; it is just better not to eat then. (Mishnah Berurah, Eliyahu Rabbah) eat4See Rambam. This includes doing work. (Eliyahu Rabbah, Biur Halachah 529:1) on erev Yom Tov after5This refers to Minchah Ketanah which starts 9-1/2 hours into the day. (Mishnah Berurah, Eliyahu Rabbah, Vilna Gaon) You should not eat a meal from a half an hour before this time. (Biur Halachah, Shulchan Aruch Harav) The Ramah 639:3 and Chok Yaakov 471 rule that on erev Sukkos you may not eat bread from noon onward. The Matteh Ephraim rules, if you were unable to eat before noon, you may eat bread before noon. Minchah,6You may eat meat, fish,or fruit even after Minchah ketanah. Even on erev Sukkos and erev Pesach. (Matteh Ephraim 625:7) just as on erev Shabbos, so that you will be able to eat the Yom Tov meal with good appetite. And if erev Yom Tov occurs on Shabbos, you must eat the third meal before Minchah ketanah.7If you did not, you should eat only a little bread, that is slightly more than a kebeitzah (see glossary). (Machatzis Hashekel, Sha’ar Hatziyun 529:10) This law also applies to the first day of Yom Tov, since it is the eve of the second day of Yom Tov.8Magein Avraham. See Biur Halachah 529:1 who questions this.
תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)