1 Samuel 14:7-10

And his armourbearer said unto him, Do all that is in thine heart: turn thee; behold, I am with thee according to thy heart. Then said Jonathan, Behold, we will pass over unto these men, and we will discover ourselves unto them. If they say thus unto us, Tarry until we come to you; then we will stand still in our place, and will not go up unto them. 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.