סימן צט סעיף א
כָּל מֻקְצֶה הָאָסוּר בְּטִלְטוּל בַּשַׁבָּת, אָסוּר גַּם בְּיוֹם טוֹב. וְיֵשׁ אוֹמְרִים, דְּגַם מֻקְצֶה מִדַּעַת, וּמֻקְצֶה מֵחֲמַת מֵאוּס, אַף עַל פִּי שֶׁמֻּתָּרִין בַּשַׁבָּת, אֲסוּרִין בְּיוֹם טוֹב. וְלָכֵן פֵּרוֹת שֶׁהִקְצָה אוֹתָם לִסְחוֹרָה, אֲסוּרִין בְּיוֹם טוֹב, אֶלָּא צָרִיךְ שֶׁיַּזְמִינֵם בְּעֶרֶב יוֹם טוֹב, דְּהַיְנוּ שֶׁיֹּאמַר, מִפֵּרוֹת אֵלּוּ אֹכַל לְמָחָר. וּבְפֵרוֹת הָעוֹמְדִין לִמָּכֵר מְעַטמְעַט, יֵשׁ לְהָקֵל (תצ"ה).
All Muktzeh, that is forbidden to be handled on Shabbos, is also forbidden to be handled on Yom Tov. Some authorities say, things that are purposely excluded from use and things excluded from use because of their filth, even though they may be handled on Shabbos, they may not be handled on Yom Tov.1Shulchan Aruch 495:4. Since some melachos are permitted for preparation of food on Yom Tov, the Sages feared people might not view Yom Tov with the proper seriousness, and, therefore, were more stringent regarding muktzeh on Yom Tov than on Shabbos. (see Mishnah Berurah 495:15) Therefore, fruits2Even though you may handle muktzeh for preparation of food, it is permitted only to remove the muktzeh in order to take the food etc., but you may not use the muktzeh itself, even for food or its preparation. (Magein Avraham, Mishnah Berurah 508:31) that were set aside for sale, are forbidden to be handled on Yom Tov, unless you designate them on erev Yom Tov by saying: "I will eat from this fruit3The Ramah 495:4 rules that only livestock must be designated, but regarding fruits etc., it is sufficient to say you will take from the pile. The Rif, Rambam, Rosh, Meiri, Magein Avraham etc. rule that even fruits must be designated and that it is necessary to make some sign or notation to this effect. The Meiri explains that the purpose of a sign is to remember which ones were selected; therefore, one who has a good memory need not make a sign. (see Biur Halachah 495:4) tomorrow." Concerning fruit that is scheduled to be sold a little at a time, you may be lenient.
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.)