Hastings' Dictionary of the Bible (1898)
YEAR, SABBAT'ICAL. In the seventh year all agricultural labor was suspended, and spontaneous productions were left to the poor, the traveller, and the wild beasts. Lev 25:1-7. This was (1) For the sake of the ground; (2) For the preservation of wild beasts; and (3) To make the people provident and sensible of dependence. The people could fish, hunt, take care of bees and flocks, repair buildings, manufacture clothes, and carry on commerce. This year was religiously observed, Deut 31:10-13. There was, moreover, a general release-, no debt to a Jew was allowed to stand, but must be forgiven.
Deut 15:1-11. , four hundred and ninety years. Whether it was ever observed is not a matter of certain record, but there is an allusion to it in 1 Mace.