So there is a price to pay for his unbelief. He will be dumb.
What do we forfeit by our unbelief? We lose the blessing of assurance and the joy of anticipating our future heavenly reward. This hope is given to us to strengthen us through the many trials of this life, so we miss out on a great deal of consolation. We also miss privileges and opportunities to serve the Lord. Because of unbelief, the older generation of the children of Israel never saw the promised land. Moses might have led the children of Israel into the promised land, but because of his outburst in striking the rock, which arose due to unbelief (Numbers 20:12), he forfeited that privilege. Because of unbelief the lord of the king of Israel heard the promise of the lifting of the siege of Samaria and the relief of the famine, but he did not eat of it himself. We forfeit service for the Lord by not believing that he can use us. By not trusting his methods and substituting carnal methods of our own we fail to reap a harvest for the Lord. The unbelieving minister builds wood hay and stubble which will not survive the judgment of God and so loses his reward.