Positive Mitzvah 121;
Negative Mitzvah 211;
Positive Mitzvah 123;Negative Mitzvah 212

Another way for the farmer to provide the poor people with their share in the field is to leave fallen stalks.

As the produce is reaped, individual stalks often fall to the ground.

The Torah commands us to leave them on the ground so the poor can collect them afterwards (see Negative Mitzvah 211).

When the farmer collects his crops, he ties sheaves of stalks together into bundles.

This makes it easier for him to gather the crop afterwards.

All he has to do is collect the bundles.

While he is collecting the stalks, one or two may fall out of his hand or the container, before he ties them into bundles.

The Torah forbids him to pick up those fallen stalks. They are left for the needy to come and collect.

A Jew must think about the needy not only in his field, but also in his vineyard.

As he is picking his clusters of ripened grapes, he must look out for those clusters of grapes that are not attached to a central stem or do not have the grapes lying one upon the other.

HaShem commands him to leave those clusters for the poor (see Negative Mitzvah 212).

This Mitzvah of "Tzedakah" applies also to vineyards (not just fields - see above).

While picking the fruit, we must look out for those clusters that do not have the grapes attached to a central stem. We should also notice those clusters that do not have grapes lying on one another.

These bundles are called "Ollelot".

It is forbidden to pick Ollelot. They must be left for the needy people who may come and collect them.