Charles Ellicott Commentary 1 Kings 13:3-4

"And he gave a sign the same day, saying, This is the sign which Jehovah hath spoken: Behold, the altar shall be rent, and the ashes that are upon it shall be poured out. And it came to pass, when the king heard the saying of the man of God, which he cried against the altar in Beth-el, that Jeroboam put forth his hand from the altar, saying, Lay hold on him. And his hand, which he put forth against him, dried up, so that he could not draw it back again to him." — 1 Kings 13:3-4 (ASV)

The sign. —Both the signs, like most miraculous signs, plainly foreshadow the thing signified. The sign, announced to lend credibility to the prediction, is itself a visible type of what that prediction foretold, in the shattering of the altar and the scattering of the ashes of the burnt-offering. The sign actually given includes, besides this, the sudden withering of the king’s hand, stretched out in defiance of the prophet—an equally plain symbol of the miserable failure of his strength and policy, when opposed to the Law and the judgment of God.

It should be noted that the withdrawal of this last sign of wrath, upon the submission of the king and the prayer of the prophet, was apparently designed to give Jeroboam one more opportunity for repentance. The last verses of the chapter (1 Kings 13:33–34) seem to imply that, but for the intervention of the old prophet of Bethel, he might still have taken that opportunity.