To not go back to take what is forgotten: That we have been prevented from taking the sheaf of what is forgotten, as it states (Deuteronomy 24:19), “and forget a sheaf in the field, do not turn back to get it.” (See Sefer HaMitzvot, Negative Commandments 214.) And the commandment of what is forgotten is also [applicable] with trees.
And this negative commandment is from the negative commandments that are rectified by a positive commandment — as anyone that transgresses and takes from what is forgotten is obligated to return it to the poor, as it states, “it shall go to the stranger, the orphan, and the widow.” And I have written in this Order regarding the sending away of the nest (Sefer HaChinukh 544) [about] any negative commandment that is rectified by a positive commandment, [that if] he performs the positive commandment, he is not lashed. But if he does not perform the positive commandment and it is also impossible to perform it any longer — for example, [if] the thing were lost or burnt — he is lashed. And the example of this is with the corner of the field, the reaping of which is a negative commandment (Sefer HaChinukh 217) — and if he reaps it, he is not liable for lashes for the reaping; as behold, he is able to “fix what he distorted” [by] giving it to the poor in its sheaves. And even if he threshed the wheat and ground and baked it, he can give the required amount of “the corner” to the poor from the bread; and behold, it is still in his hand to fix [the sin] and [so,] he is not lashed. But if an accident happens that all of that wheat gets lost or it gets burnt, he is lashed; as behold, it is impossible for him to still perform the positive commandment in it. And [so,] he has already transgressed the negative commandment and he cannot fix [it]. And this is called in the Gemara, “he did not fulfill it.” And if he lost the wheat in his [own] hands or ate all of it, all the more so is he liable for lashes for it. And this is called, “he negated it,” in the Talmud, as he was the cause for the negating of the negative commandment in his hands — a negation that can no longer be fixed. And [about] that which they said in Makkot 16a at the end of the chapter [entitled] Elu Hen HaLokin concerning the commandment of sending away the nest regarding “he fulfilled it and he did not fulfill it”: “We only have this and one other [case]” — and it is known that the other is “the corner” — as it is concluded there, “But rather ‘this and one other’ is about that,” meaning to say, [about] “the corner,” and the matter stays like that — their intention is not that it wants to say that only sending away the nest and “the corner” have this law of “he fulfilled it and he did not fulfill it.” But rather their intention was to say “the corner” and all that have a similar law — such as fallen grapes, that which is forgotten, the fallen sheaves, and the bunchless grapes — as each one of these is a negative commandment that [involves] an act, and it is [just] as likely with them to have all that is likely with “the corner,” regarding “he fulfilled it and he did not fulfill it” or “he negated it and he did not negate it.” As the verse from which we learned that in “the corner” there is a positive commandment, is that which is written about it (Leviticus 19:10), “you shall leave them for the poor and the stranger.” And with the sheaf of what is forgotten and the others mentioned, there is likewise about them, “you shall leave them for the stranger and the orphan and the widow,” or “it shall go to the stranger, the orphan, and the widow.” And take this matter and understand it, as it is a little hidden, in that the language in the Gemara is somewhat unclear — in that which they said, “We only have this and one other [case].”
I have written about the roots of the commandment and its content in the positive commandment of that which is forgotten in this Order (Sefer HaChinukh 592).
שֶׁלֹּא יָשׁוּב לָקַחַת הַשִּׁכְחָה – שֶׁנִּמְנַעְנוּ מִלָּקַחַת עֹמֶר הַשִּׁכְחָה, שֶׁנֶּאֱמַר (דברים כד יט) וְשָׁכַחְתָּ עֹמֶר בַּשָּׂדֶה לֹא תָשׁוּב לְקַחְתּוֹ (עי' ספהמ"צ להרמב"ם לאוין ריד). וּמִצְוַת הַשִּׁכְחָה הִיא גַּם כֵּן בָּאִילָן.
To not go back to take what is forgotten: That we have been prevented from taking the sheaf of what is forgotten, as it states (Deuteronomy 24:19), “and forget a sheaf in the field, do not turn back to get it.” (See Sefer HaMitzvot, Negative Commandments 214.) And the commandment of what is forgotten is also [applicable] with trees.
וְזֶה הַלָּאו הוּא מִן הַלָּאוִין הַנִּתָּקִין לַעֲשֵׂה, שֶׁכָּל מִי שֶׁעָבַר וְלָקַח הַשִּׁכְחָה חַיָּב לְהַחְזִיר אוֹתָהּ לָעֲנִיִּים, שֶׁנֶּאֱמַר לַגֵּר לַיָּתוֹם וְלָאַלְמָנָה יִהְיֶה. וּכְבָר כָּתַבְתִּי בְּסֵדֶר זֶה בְּעִנְיַן שִׁלּוּחַ הַקֵּן (מצוה תקמד), שֶׁכָּל לֹא תַעֲשֶׂה הַנִּתָּק לַעֲשֵׂה קִיֵּם עֲשֵׂה שֶׁבּוֹ אֵינוֹ לוֹקֶה, וְאִם לֹא קִיְּמוֹ וְגַם אִי אֶפְשָׁר לוֹ לְקַיְּמוֹ עוֹד, וּכְגוֹן שֶׁאָבַד אוֹ נִשְׂרַף אוֹתוֹ הַדָּבָר, לוֹקֶה. וְהַמָּשָׁל בָּזֶה, הַפֵּאָה שֶׁיֵּשׁ לָאו בִּקְצִירָתָהּ (מצוה ריז), וְאִם קָצַר אוֹתָהּ לֹא יִתְחַיֵּב מַלְקוּת עַל הַקְּצִירָה, שֶׁהֲרֵי יָכוֹל לְתַקֵּן אֶת אֲשֶׁר עִוֵּת שֶׁיִּתְּנֶנָּה לַעֲנִיִּים בְּשִׁבֳּלִים, וַאֲפִילּוּ דָּשׁ הַחִטָּה וּטְחָנָהּ וַאֲפָאָהּ יִתֵּן מֵהַפַּת שִׁעוּר הַפֵּאָה לָעֲנִיִּים, וַהֲרֵי עֲדַיִן בְּיָדוֹ לְתַקֵּן וְלֹא יִלְקֶה. אֲבָל אִם יִקֶר מִקְרֶה שֶׁתֹּאבַד הַחִטָּה הַהִיא כֻּלָּהּ אוֹ תִּשָּׂרֵף, יִלְקֶה, שֶׁהֲרֵי אִי אֶפְשָׁר לוֹ עוֹד לְקַיֵּם עֲשֵׂה שֶׁבּוֹ, וּכְבָר עָבַר עַל הַלָּאו וְלֹא יוּכַל לְתַקֵּן, וְזֶה יִקָּרֵא בַּגְּמָרָא לֹא קִיְּמוֹ. וְאִם הוּא בְּיָדָיו אִבֵּד הַחִטָּה אוֹ אֲכָלָהּ כֻּלָּהּ כָּל שֶׁכֵּן שֶׁיִּתְחַיֵּב בָּהּ הַמַּלְקוּת, וְזֶה נִקְרָא בַּגְּמָרָא בִּטְּלוֹ, כִּי הוּא הַגּוֹרֵם לְבַטֵּל הַלָּאו בִּטּוּל שֶׁאֵין בּוֹ עוֹד תַּקָּנָה בְּיָדָיו. וּמָה שֶׁאָמְרוּ בְּמַכּוֹת (טז, א) בְּסוֹף פֶּרֶק אֵלּוּ הֵן הַלּוֹקִין גַּבֵּי מִצְוַת שִׁלּוּחַ הַקֵּן בְּעִנְיָן קִיְּמוֹ וְלֹא קִיְּמוֹ אָנוּ אֵין לָנוּ אֶלָּא זֹאת וְעוֹד אַחֶרֶת, וְנוֹדַע שֶׁהָאַחֶרֶת הַהִיא הִיא פֵּאָה, כִּדְמַסִּיק הָתָם, אֶלָּא זֹאת וְעוֹד אַחֶרֶת אַהָא, כְּלוֹמַר מִן הַפֵּאָה, וְנִשְׁאַר הָעִנְיָן כֵּן, אֵין הַכַּוָּנָה שֶׁיִּרְצֶה לוֹמַר שֶׁשִּׁלּוּחַ הַקֵּן וְהַפֵּאָה בִּלְבַד הֵן בְּדִין זֶה דְּקִיְּמוֹ וְלֹא קִיְּמוֹ, אֲבָל כַּוָּנָתָם לוֹמַר הַפֵּאָה וְכָל מָה שֶׁדִּינוֹ כָּמוֹהָ, כְּמוֹ הַפֶּרֶט וְהַשִּׁכְחָה וְהַלֶּקֶט וְהָעוֹלֵלוֹת, שֶׁכָּל אֶחָד מֵאֵלּוּ הוּא לָאו שֶׁיֵּשׁ בּוֹ מַעֲשֶׂה, וְיִתָּכֵן בָּהֶם כָּל מָה שֶׁיִּתָּכֵן בְּפֵאָה מִן קִיְּמוֹ וְלֹא קִיְּמוֹ אוֹ בִּטְּלוֹ וְלֹא בִּטְּלוֹ, כִּי הַכָּתוּב שֶׁלָּמַדְנוּ מִמֶּנּוּ שֶׁיֵּשׁ בְּפֵאָה קוּם עֲשֵׂה הוּא מָה שֶׁכָּתוּב בָּהּ לֶעָנִי וְלַגֵּר תַּעֲזֹב אֹתָם (ויקרא יט י), וּבְעֹמֶר הַשִּׁכְחָה וּבִשְׁאָר הַנִּזְכָּרִים יֵשׁ בָּהֶן כְּמוֹ כֵן לַגֵּר לַיָּתוֹם וְלָאַלְמָנָה תַּעֲזֹב אֹתָם, אוֹ לַגֵּר לַיָּתוֹם וְלָאַלְמָנָה יִהְיֶה. וְקַבֵּל זֶה הָעִנְיָן וַהֲבִינֵהוּ, שֶׁהוּא נֶעֱלָם קְצָת מֵאֲשֶׁר בָּא בַּגְּמָרָא הַלָּשׁוֹן סָתוּם בְּמִקְצָת, שֶׁאָמְרוּ אָנוּ אֵין לָנוּ אֶלָּא זֹאת וְעוֹד אַחֶרֶת.
And this negative commandment is from the negative commandments that are rectified by a positive commandment — as anyone that transgresses and takes from what is forgotten is obligated to return it to the poor, as it states, “it shall go to the stranger, the orphan, and the widow.” And I have written in this Order regarding the sending away of the nest (Sefer HaChinukh 544) [about] any negative commandment that is rectified by a positive commandment, [that if] he performs the positive commandment, he is not lashed. But if he does not perform the positive commandment and it is also impossible to perform it any longer — for example, [if] the thing were lost or burnt — he is lashed. And the example of this is with the corner of the field, the reaping of which is a negative commandment (Sefer HaChinukh 217) — and if he reaps it, he is not liable for lashes for the reaping; as behold, he is able to “fix what he distorted” [by] giving it to the poor in its sheaves. And even if he threshed the wheat and ground and baked it, he can give the required amount of “the corner” to the poor from the bread; and behold, it is still in his hand to fix [the sin] and [so,] he is not lashed. But if an accident happens that all of that wheat gets lost or it gets burnt, he is lashed; as behold, it is impossible for him to still perform the positive commandment in it. And [so,] he has already transgressed the negative commandment and he cannot fix [it]. And this is called in the Gemara, “he did not fulfill it.” And if he lost the wheat in his [own] hands or ate all of it, all the more so is he liable for lashes for it. And this is called, “he negated it,” in the Talmud, as he was the cause for the negating of the negative commandment in his hands — a negation that can no longer be fixed. And [about] that which they said in Makkot 16a at the end of the chapter [entitled] Elu Hen HaLokin concerning the commandment of sending away the nest regarding “he fulfilled it and he did not fulfill it”: “We only have this and one other [case]” — and it is known that the other is “the corner” — as it is concluded there, “But rather ‘this and one other’ is about that,” meaning to say, [about] “the corner,” and the matter stays like that — their intention is not that it wants to say that only sending away the nest and “the corner” have this law of “he fulfilled it and he did not fulfill it.” But rather their intention was to say “the corner” and all that have a similar law — such as fallen grapes, that which is forgotten, the fallen sheaves, and the bunchless grapes — as each one of these is a negative commandment that [involves] an act, and it is [just] as likely with them to have all that is likely with “the corner,” regarding “he fulfilled it and he did not fulfill it” or “he negated it and he did not negate it.” As the verse from which we learned that in “the corner” there is a positive commandment, is that which is written about it (Leviticus 19:10), “you shall leave them for the poor and the stranger.” And with the sheaf of what is forgotten and the others mentioned, there is likewise about them, “you shall leave them for the stranger and the orphan and the widow,” or “it shall go to the stranger, the orphan, and the widow.” And take this matter and understand it, as it is a little hidden, in that the language in the Gemara is somewhat unclear — in that which they said, “We only have this and one other [case].”
מִשָּׁרְשֵׁי הַמִּצְוָה. וְעִנְיָנָהּ כָּתַבְתִּי בְּמִצְוַת עֲשֵׂה דְּשִׁכְחָה שֶׁבְּסֵדֶר זֶה (מצוה תקצב).
I have written about the roots of the commandment and its content in the positive commandment of that which is forgotten in this Order (Sefer HaChinukh 592).