And he gave a sign the same day, saying, this is the sign which the Lord hath spoken,.... As a confirmation of the truth of what the prophet had said, and for the proof of his being a true prophet of the Lord:
behold, the altar shall be rent; of itself, by an invisible hand, by the power of God:
and the ashes that are upon it shall be poured out; signifying it should be entirely demolished, not only shaken but destroyed, so as not to be capable of retaining the ashes on it; this was an emblem of the utter abolition of idolatry here in future times.