3,127. Harvesting Half the Field and Something Else Happens to the Other Half

Hilchos Matnos Aniyim 2:5

If the owner of a field harvested half of it and then thieves harvested the other half, the field is exempt from peah since the obligation applied to the remaining half, which was harvested by thieves. However, if thieves first harvested half of it and then the owner harvested the other half, then he must leave peah based on what he harvested. If the owner harvested half the field and then sold the other half, the buyer must leave peah for the whole field. If he harvested half and consecrated the other half, the one who redeems it must leave peah for the whole field. If he harvested half the field and consecrated the produce, he must leave peah for the whole field from the other half.

Hilchos Matnos Aniyim 2:6

Let’s say that someone harvested the grapes from his vineyard to sell in the market, but he intended to leave the rest to press into wine. If he harvests the grapes for sale from either side, he leaves peah for what he harvests to press based on how much remains; if he harvests grapes for sale from just one side, then he leaves enough peah for the whole field from what remains. Since he only harvested from one side, he is not considered to have been harvesting randomly, in which case those grapes would have been exempt from peah. Similarly, if someone harvests stalks of grain a little at a time and brings them home, he is exempt from leket, shich’cha and peah. This is the case even if a person harvests his whole field this way.