What does 1 Samuel 6:12 mean?

The cows headed straight down the road to Beth Shemesh, never turning aside. They kept lowing as they went. The Philistine rulers followed them all the way to the border of Beth Shemesh. 1 Samuel 6:12 - Modern Text Bible

(The cows, without any human guidance, go directly to Israel, which the Philistines see as a sign that God is behind all that's happened.)