Why did Moses deliberately destroy the stone tables containing the original divinely inscribed commandments?

Exodus 32:16 And the tables were the work of God, and the writing was the writing of God, graven upon the tables. 32:17 And when Joshua heard the noise of the people as they shouted, he said unto Moses, There is a noise of war in the camp. 32:18 And he said, It is not the voice of them that shout for mastery, neither is it the voice of them that cry for being overcome: but the noise of them that sing do I hear. 32:19 And it came to p, as soon as he came nigh unto the camp, that he saw the calf, and the dancing: and Moses' anger waxed hot, and he cast the tables out of his hands, and brake them beneath the mount.