1 Samuel 14:10
But if they say thus, Come up unto us; then we will go up: for the LORD hath delivered them into our hand: and this shall be a sign unto us. But if they say thus, Come up unto us; then we will go up: for the LORD hath delivered them into our hand: and this shall be a sign unto us.
Jonathan set this sign with his armor-bearer: if the Philistines said, come up to us, the two would advance, taking those words as proof that the Lord had delivered the Philistines into their hand and would prosper their attack. Because of Saul's sin in his presumptuous offering, God would not give Saul the honor of vanquishing the Philistines, but chose Jonathan, a man who feared the Lord, as the instrument to deliver Israel. Jonathan and his armor-bearer, himself a man of faith and prayer, withdrew secretly from the camp at Geba lest they be opposed, went down into the gorge separating the armies, and showed themselves to the Philistine fortress at Michmash.
The sign was agreed upon with earnest prayer for God's counsel and direction, leaving the outcome in God's hands. Their advance was not mere human rashness or presumption, but was moved upon by God by a divine impulse. Jonathan and his companion put their hope in God rather than their own strength, trusting that there is no restraint to the Lord and that He can save by many or by few.
When the Philistines tauntingly challenged them to come up to be punished, Jonathan and his armor-bearer recognized the agreed token and treated it as evidence that the Lord would prosper their undertaking. God worked through Jonathan and his armor-bearer to defeat the Philistines and deliver Israel, and the angels of the Lord prospered their action. That victory made clear it came from God and not from Israel's strength or merit.