1 Samuel 6:7-9

Now then, make a new cart and prepare two milk cows on which a yoke has never been placed; and hitch the cows to the cart and take their calves back home, away from them. Then take the ark of the LORD and put it on the cart; and put the articles of gold which you are returning to Him as a guilt offering in a box beside it. Then send it away [without a driver]. But watch, if it goes up by the way of its own territory to Beth-shemesh, then [you will know that] He has done us this great evil. But if not, then we will know that it was not His hand that struck us; this disaster happened to us by chance.”