1 Samuel 6:9-10

9Then watch: If it goes up the road to its homeland toward Beth-shemesh, it is the Lord who has made this terrible trouble for us. However, if it doesn’t, we will know that it was not his hand that punished us — it was just something that happened to us by chance.”

10The men did this: They took two milk cows, hitched them to the cart, and confined their calves in the pen.