There was a trembling in the camp, in the field, and among all the people; the garrison, and the spoilers, they also trembled; and the earth quaked: so there was an exceeding great trembling.
Half a furrow of land (1 Samuel 14:14) was half a parcel of land that a yolk of oxen could plow in one day. Evidently God assisted Jonathan by sending a mild earthquake to unnerve the Philistines further (1 Samuel 14:15; cf. Deuteronomy 7:23).