In agriculture, the reaper would cut stalks of grain during the time of harvest and the plowman would prepare the ground for another planting. The idea being conveyed is of a harvest so abundant that after many months of trying to collect one crop, it will be time for the new crop to be planted.1
13 “Behold, the days are coming,” declares the LORD, “when the plowman shall overtake the reaper and the treader of grapes him who sows the seed; the mountains shall drip sweet wine, and all the hills shall flow with it.