There ate instances throughout the entire Bible when God or angelic beings become direct participants in human affairs. God can enter a prison and force chains to fall off. Peter and Saul had that experience. In each instance, there was the same trembling. It happened during the resurrection of Jesus. It so trembled that the soldiers were like dead. It again happened when some angels went to hear Paul and Silas sing in prison. This trembling appear to happen when heaven steps into physical affairs. In the verse above, the garrison and the spoilers experienced the trembling. God had taken over the command from Jonathan and his armour bearer. It didn’t take the army of Israel to cause the trembling, it took two people of faith and God on their side. Don’t buy the fear from the devil. You’re better with God than the enemy will accept. From the spectators point of view, the watchmen of Israel saw their trouble vanishing. Oh Lord, send us help. So Saul called for a census. Only two were missing, Jonathan and his armour bearer, not a brigade. This could only be the hand of God. Here is David: Psa.114:7. This is the New Testament:Mk 16:8. Our God reigns, let the earth tremble. Sing that. It’s time for change.
And there was trembling in the host, in the field, and among all the people: the garrison, and the spoilers, they also trembled, and the earth quaked: so it was a very great trembling. 1 Samuel 14:15 KJV