Negative Commandments #186 & 187
Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos)
By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
Second Section – the Negative Commandments
186. It is a negative commandment for a worker "do not eat from anything that grows from the ground while he is working, but only after he has completed the work"
As it states in Devarim (Deuteronomy) 23:26, "you shall not lift your sickle on your friend's grain." It is taught in Oral Tradition that while one is working, he is not allowed to lift his sickle to eat any of it.
187. It is a negative commandment on a worker "do not take in his hand anything that he has worked on and do not take more than what he eats and give it to others."
As it states in Devarim 23:25, "but you shall not put it in your vessels." (see Positive Commandment #65)
This applies in all places and at all times, for men and for women.