Negative Mitzvot 267, 268

Positive Mitzvah 201 allows a hired worker to eat from the fruit or grain that he is harvesting, but the worker must realize that he was hired to do a job.

This Negative Mitzvah forbids a worker who is hired to harvest from reaping crops for himself or eating when he is not allowed.

It also forbids a person hired to do other work besides harvesting from reaping grain for himself and eating while he is working for his employer.

As mentioned, a hired worker may eat from the fruit or grain that he is harvesting. However, there are limits to how much he is allowed to eat.

It would be cruel to stop a worker from eating entirely, but this Negative Mitzvah forbids a worker from taking more than a fair share.

A hired worker in a vineyard may only eat enough grapes to satisfy his hunger. He is not allowed to gather grapes for himself and pack them away to take home or eat later.