3,128. Consecrating a Field of Standing Grain

Hilchos Matnos Aniyim 2:7

If someone harvests his whole field before it’s ripe and it hasn’t reached a third of its growth, he need not leave peah. Once it reaches a third of its growth, then he is obligated in peah. The same is true of the fruit of trees: once they reach a third of their growth, they are obligated in peah.

Hilchos Matnos Aniyim 2:8

If someone consecrates his field while the grain is standing and he redeems it while the grain is standing, he must leave peah from it. If the Temple treasurer had the field harvested and then then the owner redeemed it, the field is exempt. This is because at the time when the obligation of peah would have kicked in (i.e., when harvesting), the field was consecrated and therefore exempt.