The Philistines fight against Keilah - Keilah was a fortified town in the tribe of Judah near to Eleutheropolis, on the road to Hebron.
Rob the threshing-floors - This was an ancient custom of the Philistines, Midianites, and others. See Jdg 6:4. When the corn was ripe and fit to be threshed, and they had collected it at the threshing-floors, which were always in the open field, then their enemies came upon them and spoiled them of the fruits of their harvest.