וְכֹל פַּנְיָא דְּמַעֲלֵי שַׁבְּתָא הֲוָה מְשַׁדַּר שְׁלוּחָא לְשׁוּקָא, וְכֹל יַרְקָא דַּהֲוָה פָּיֵישׁ לְהוּ לְגִינָּאֵי, זַבֵּין לֵיהּ וְשָׁדֵי לֵיהּ לְנַהֲרָא. וְלִיתְּבֵיהּ לַעֲנִיִּים! זִמְנִין דְּסָמְכָא דַּעְתַּיְיהוּ וְלָא אָתוּ לְמִיזְבַּן. וְלִשְׁדְּיֵיהּ לִבְהֵמָה! קָסָבַר: מַאֲכַל אָדָם אֵין מַאֲכִילִין לִבְהֵמָה.
Rafram bar Pappa further relates: And every Shabbat eve, in the afternoon, Rav Huna would send a messenger to the marketplace, and he would purchase all the vegetables that were left with the gardeners who sold their crops, and throw them into the river. The Gemara asks: But why did he throw out the vegetables? Let him give them to the poor. The Gemara answers: If he did this, the poor would sometimes rely on the fact that Rav Huna would hand out vegetables, and they would not come to purchase any. This would ruin the gardeners’ livelihood. The Gemara further asks: And let him throw them to the animals. The Gemara answers: He holds that human food may not be fed to animals, as this is a display of contempt for the food.
וְלָא לִיזְבְּנֵיהּ כְּלָל! נִמְצֵאתָ מַכְשִׁילָן לֶעָתִיד לָבֹא.
The Gemara objects: But if Rav Huna could not use them in any way, he should not purchase the vegetables at all. The Gemara answers: If nothing is done, you would have been found to have caused a stumbling block for them in the future. If the vegetable sellers see that some of their produce is left unsold, the next week they will not bring enough for Shabbat. Therefore, Rav Huna made sure that the vegetables were all bought, so that the sellers would continue to bring them.