A sign. See on 2 Kings 19:29. Hezekiah and the people of Judah are assured that God will give them a sign, as He often did (Isa. 7:11, 14; 38:8), in pledge of the fulfillment of the accompanying prediction. The Assyrian invasion had put a stop to all normal agricultural activities, but the people are assured of an adequate supply of food. The following year may have been a sabbatical year, during which enough food would grow of itself. The third year, however, would bring a resumption of normal life and activities. The fulfillment of this prediction within the specified time would be a token of the certain fulfillment of the wider promise in vs. 31, 32.