What does 1 Samuel 14:12 mean?

The men at the outpost shouted to Jonathan and his armor-bearer, 'Come up here, and we'll teach you a lesson!' Jonathan said to his armor-bearer, 'Follow me—the Lord has handed them over to Israel.' 1 Samuel 14:12 - Modern Text Bible

(The Philistines' challenge is exactly the sign Jonathan was looking for, so he moves forward in faith.)