1 Samuel 14:14-16

That first slaughter which Jonathan and his armor bearer made was about twenty men within about half a [plow] furrow in a plot of land [the area of which a yoke of oxen could plow in a day]. And there was trembling in the [Philistine] camp, in the field, and among all the people; even the garrison and the raiding party trembled [in fear], and the earth quaked and it became a trembling and terror from God. Saul’s watchmen in Gibeah of Benjamin looked, and behold, the multitude melted away and they went here and there.