The 268th prohibition is that a hired worker is forbidden from taking from the produce he is working with, more than he needs for his meal.

The source of this prohibition is G‑d's statement1 (exalted be He), "You may eat as many grapes as you desire to satisfy your hunger. However, you may not put any into your vessel."

The details of this mitzvah are explained in the 7th chapter of tractate Bava Metzia. There it is explained what one may eat, and what one may not eat, and that if one eats, he transgresses the prohibition, "You may not put any into your vessel."