3,705. Clearing a Field During Shemittah

Hilchos Shemittah v’Yoveil 1:16

The Sages used to permit gathering wood, stones and grass from one’s field so long as he only takes the larger ones, making it clear that he isn’t trying to clear the land; he could take both the small and the large from a neighbor’s field. Eventually, however, the number of people violating this law increased, with people clearing their fields and saying that they were only taking the larger. The Sages therefore prohibited a person gathering wood and stones from his own field, only allowing him to do so from a neighbor’s field. Even then, one is not permitted to do so in order to exchange favors.

Hilchos Shemittah v’Yoveil 1:17

If a person’s animal is in his field, he may gather grass and bring it to the animal. This is because the animal's presence makes his intentions clear. Similarly, if one’s stove is there (as might have been the case in former times), he may gather what he needs for kindling and light it, since the stove’s presence makes his intentions clear.