'Proof' in the Bible

Later that same day, he gave them a special display of power of what was to come when he said, "Here's proof that the LORD has decreed this: Look! This altar will be split apart and the ashes that are on it will spill out."

Also, the altar broke apart and the ashes that were on it spilled out from the altar, providing just the proof that the man of God had predicted in his message from the LORD!