Adam Clarke on Deuteronomy 25:2

The judge shall cause him to lie down, and to be beaten before his face - This precept is literally followed in China; the culprit receives in the presence of the magistrate the punishment which the law directs to be inflicted. Thus then justice is done, for the magistrate sees that the letter of the law is duly fulfilled, and that the officers do not transgress it, either by indulgence on the one hand, or severity on the other. The culprit receives nothing more nor less than what justice requires.