Why was the Jew beaten?

Chauvelin sends his soldiers to find Percy -- but before he leaves, realizes that the Jew has been left unpunished. He tells his soldiers to bring the Jew. He tells the Jew that the deal they made was clear -- and that not only did his horse fail to overtake Percy's, but that now even the fugitives have gone free. He orders his soldiers to beat the Jew mercilessly, which they do while Chauvelin watches and Marguerite lays unconscious.