(א) הַקּוֹצֵר אֶת שָׂדֵהוּ לֹא יִקְצֹר אֶת כָּל הַשָּׂדֶה כֻּלָּהּ אֶלָּא יַנִּיחַ מְעַט קָמָה לָעֲנִיִּים בְּסוֹף הַשָּׂדֶה שֶׁנֶּאֱמַר (ויקרא כג כב) "לֹא תְכַלֶּה פְּאַת שָׂדְךָ בְּקֻצְרֶךָ" אֶחָד הַקּוֹצֵר וְאֶחָד הַתּוֹלֵשׁ. וְזֶה שֶׁמַּנִּיחַ הוּא הַנִּקְרָא פֵּאָה:
One who reaps his field should not reap the whole field entirely but rather he should leave a little bit of standing grain for the poor at the edge of the field, as it is written, (Lev. 23:22) You shall not reap all the way to the edges of the field. It is the same whether one is reaping [with a tool] or plucking [by hand], and that which is left is what Scripture refers to as péah [the "corner"].
(ד) וְכֵן בְּלֶקֶט כְּשֶׁקּוֹצֵר וּמְאַלֵּם לֹא יְלַקֵּט הַשִּׁבֳּלִים הַנּוֹפְלוֹת בִּשְׁעַת הַקָּצִיר אֶלָּא יַנִּיחֵם לָעֲנִיִּים שֶׁנֶּאֱמַר (ויקרא יט ט) (ויקרא כג כב) "וְלֶקֶט קְצִירְךָ לֹא תְלַקֵּט".
And so it is with leket [overlooked gleanings] as one reaps and binds, one may not gather the fallen stalks at the time of reaping, but rather one should leave them for the poor, as it is said, (Lev. 23:22) Or gather the gleanings of your harvest.
וְכֵן הַמְעַמֵּר וְשָׁכַח אֲלֻמָּה אַחַת בַּשָּׂדֶה הֲרֵי זֶה לֹא יִקָּחֶנָּה שֶׁנֶּאֱמַר (דברים כד יט) "וְשָׁכַחְתָּ עֹמֶר בַּשָּׂדֶה לֹא תָשׁוּב לְקַחְתּוֹ".
So also with one who stacks sheaves and has forgotten a sheaf in the field. This person may not recover it, as it is said, (Deut. 24:19) And overlook a sheaf in the field, do not turn back to get it.
(כב) וּֽבְקֻצְרְכֶ֞ם אֶת־קְצִ֣יר אַרְצְכֶ֗ם לֹֽא־תְכַלֶּ֞ה פְּאַ֤ת שָֽׂדְךָ֙ בְּקֻצְרֶ֔ךָ וְלֶ֥קֶט קְצִירְךָ֖ לֹ֣א תְלַקֵּ֑ט לֶֽעָנִ֤י וְלַגֵּר֙ תַּעֲזֹ֣ב אֹתָ֔ם אֲנִ֖י יְהוָ֥ה אֱלֹהֵיכֶֽם׃ (ס)
(22) And when you reap the harvest of your land, you shall not reap all the way to the edges of your field, or gather the gleanings of your harvest; you shall leave them for the poor and the stranger: I the LORD am your God.