1 Samuel 14:21-22

21Moreover the Hebrews who were with the Philistines before that time, who went up with them into the camp from the surrounding country, they also joined the Israelites who were with Saul and Jonathan.

22Likewise all the men of Israel who had hidden in the mountains of Ephraim, when they heard that the Philistines fled, they also followed hard after them in the battle.