Why does the Torah instruct the farmer to leave pe’ah in his field for the poor to cut? Wouldn’t it be easier if he cut it for them and distributed it, like other matnos aniyim?
R’ Aharon Bakst gave a mashal: imagine a mother who is angry at her child and instead of preparing his peanut butter sandwich for lunch and giving it to him herself, she allows his older brother to make the lunch and put it in his lunchbox. The loss of connection to his mother would be more painful to the child than having to eat whatever his older brother concocts.
By telling the farmer to leave the wheat uncut and unharvested, Hashem allows the poor person to have a connection directly to the land of Eretz Yisrael, the “mother” earth where his sustenance comes from.
Chazal tell us that the Amoraim would kiss the rocks of Eretz Yisrael before leaving the country. They treated the land like like giving your mother a hug and kiss before you go on a trip.
From Divrei Chaim, here.