Exodus 23:9-11

9Do not oppress a foreign resident, since you yourselves know how it feels to be foreigners; for you were foreigners in the land of Egypt.

10For six years you are to sow your land and gather its produce, 11but in the seventh year you must let it rest and lie fallow, so that the poor among your people may eat from the field and the wild animals may consume what they leave. Do the same with your vineyard and olive grove.