Deuteronomy 23:25

Catholic Public Domain Version

If you enter into your friend's grain field, you may break off the ears, and rub them in your hand, but you may not reap them with a sickle."

See the chapter Copy

And again, while the Lord was walking through the ripe grain on the Sabbath, his disciples, as they advanced, began to separate the ears of grains.

Upon entering your neighbor's vineyard, you may eat as many grapes as you please. But you may not carry any out with you.