Leviticus 25:3-5
25:3 Six years you may sow your field, and six years you may prune your vineyard and gather the produce,
25:4 but in the seventh year the land must have a Sabbath of complete rest – a Sabbath to the Lord. You must not sow your field or prune your vineyard.
25:5 You must not gather in the aftergrowth of your harvest and you must not pick the grapes of your unpruned vines; the land must have a year of complete rest.