Reference for Pesachim 2:1
כָּל שָׁעָה שֶׁמֻּתָּר לֶאֱכֹל, מַאֲכִיל לַבְּהֵמָה לַחַיָּה וְלָעוֹפוֹת, וּמוֹכְרוֹ לַנָּכְרִי, וּמֻתָּר בַּהֲנָאָתוֹ. עָבַר זְמַנּוֹ, אָסוּר בַּהֲנָאָתוֹ, וְלֹא יַסִּיק בּוֹ תַּנּוּר וְכִירָיִם. רַבִּי יְהוּדָה אוֹמֵר, אֵין בִּעוּר חָמֵץ אֶלָּא שְׂרֵפָה. וַחֲכָמִים אוֹמְרִים, אַף מְפָרֵר וְזוֹרֶה לָרוּחַ אוֹ מַטִּיל לַיָּם:
So long as he is permitted to eat, he feeds it to beasts, animals, and birds. [The fact that we do not have (the uniform structure): "So long as he eats, he feeds," but the dual structure, indicates that two (different) men are intended, viz.: "So long as a Cohein is permitted to eat terumah, an Israelite may feed chullin to his beast," our Mishnah being in accordance with R. Gamliel, who says (1:5): "Chullin is eaten all four hours, and terumah, all five." The halachah, however, is not in accordance with him, but both terumah and chullin are eaten all four, "suspended" all of the fifth, and burned at the beginning of the sixth.] ("he feeds it to beasts, animals, and birds":) [It is necessary to state all. For if only "beasts" were stated, we would assume that with a beast, where what is left over can be seen and burned, it is permitted; but with an animal, such as a marten, a cat, and a weasel, where what is left over is generally hidden, it is forbidden. (We must, therefore, be apprised otherwise.) And if only "animals" were stated, we would assume that it is permitted because an animal hides what it leaves over, so that the owner is not in transgression of "bal yeraeh" ("It may not be seen"); but if a beast leaves something over, the owner might not remember to burn it and he would be in transgression of "bal yeraeh," so that I might think it were forbidden. We must, therefore, be apprised otherwise. And since we are taught "beasts" and "animals," we are also taught "birds."] And he may sell it to a gentile, [as opposed to the view of Beth Shammai, who say that one is forbidden to sell his chametz to a gentile unless he knows that he will finish it before Pesach, an Israelite being commanded to remove it from the world and (to see to it) that it not remain.], and it is permitted to derive benefit from it [i.e., from its ashes. If he burned it before the time that it is forbidden, he is permitted to derive benefit from its ashes even after the time that it is forbidden.] Once its time has passed, [i.e., when the sixth hour has arrived, even though it is only rabbinically interdicted], it is forbidden to derive benefit from it, [just as if derivation of benefit were prohibited by the Torah. So that if he betrothed a woman with it, we do not grant validity to his betrothal. And even hardened chametz, such as grain on which (roof-) drippings have fallen, which even on Pesach itself is only rabbinically interdicted — if he betrothed a woman with it on the fourteenth (of Nissan) when the sixth hour had arrived, we grant no validity to his betrothal.], and he may not kindle oven or stove with it. [This must be stated vis-à-vis R. Yehudah, who says that there is no removal of chametz but burning. We might think that while burning it one could derive benefit from it. We must, therefore, be apprised otherwise, that even in the (regular) course of its removal it is forbidden to derive benefit from it once the time of its prohibition has arrived.] R. Yehudah says: There is no removal of chametz but burning [He derives it from "nothar" (left-over sacrificial portions), from which benefit may not be derived, which is punishable by kareth, like chametz, and which is commanded to be burned, and not (to be disposed of) in any other manner.]; and the sages say: It is also permitted to scatter it to the winds or cast it into the sea. [The rabbis do not derive it from nothar, for this (derivation) is controverted by (the law of) a stoned ox, which though forbidden for eating and derivation of benefit, and punishable by kareth, does not require burning.]