Reference for Peah 2:7

שָׂדֶה שֶׁקְּצָרוּהָ כּוּתִים, קְצָרוּהָ לִסְטִים, קִרְסְמוּהָ נְמָלִים, שְׁבָרַתָּהּ הָרוּחַ אוֹ בְהֵמָה, פְּטוּרָה. קָצַר חֶצְיָהּ וְקָצְרוּ לִסְטִים חֶצְיָהּ, פְּטוּרָה, שֶׁחוֹבַת הַפֵּאָה בַּקָּמָה:

If a field was harvested by non-Jews, harvested by robbers, chewed up by ants, or broken by wind pr animals, it is exempt [from <i>Peah</i>]. If he [the owner] harvested half and [then] robbers harvested half, it is exempt since the obligation of <i>Peah</i> applies only regarding standing grain.

Jastrow

Jastrow