1 Samuel 6:8-12

Then take the ark of the Lord and place it on the cart; and put the articles of gold which you return to Him as a guilt offering in a saddlebag by its side. Then send it away that it may go.

But watch: if it goes up by the way of its own territory to Beth-shemesh, then He has done this great evil to us. But if not, then we will know that it was not His hand that struck us; it happened to us by chance.”

Then the men did so: they took two milk cows and hitched them to the cart, and shut in their calves at home.

And they put the ark of the Lord on the cart, and the saddlebag with the gold mice and the likenesses of their tumors.

Now the cows went straight in the direction of Beth-shemesh; they went on the same road, bellowing as they went, and did not turn off to the right or to the left. And the governors of the Philistines followed them to the border of Beth-shemesh.