Exodus 23:11-12

But the seventh year thou shalt let it [the land] rest and lie still; that the poor of thy people may eat: and what they leave the beass of the field shall eat. In like manner thou shalt deal with thy vineyard, and with thy oliveyard.

Six days thou shalt do they work, and on the seventh day thou shalt rest: that thine ox and thine ass may rest, and the son of thy handmaid, and the stranger, may be refreshed.