Deuteronomy 25:1-4
25:1 If controversy arises between people, they should go to court for judgment. When the judges hear the case, they shall exonerate the innocent but condemn the guilty.
25:2 Then, if the guilty person is sentenced to a beating, the judge shall force him to lie down and be beaten in his presence with the number of blows his wicked behavior deserves.
25:3 The judge may sentence him to forty blows, but no more. If he is struck with more than these, you might view your fellow Israelite with contempt.
25:4 You must not muzzle your ox when it is treading grain.