“Seemeth” is not in the original. Render it as: Is it too little for you, i. e. “is it less than your dignity demands?”
Related Commentaries of Numbers 16:9
Numbers 16:9
9 Seemeth it but a small thing unto you, that the God of Israel hath separated you from the congregation of Israel, to bring you near to himself to do the service of the tabernacle of the LORD, and to stand before the congregation to minister unto them?