Philo Judaeus De Decalogo 140

[140] Moreover, they also commit a third violation of the law, which is more grievous than either of those which have been mentioned before; for, when there is a scarcity of demonstrations, either by reasons or by letters, then those who have questions in dispute betake themselves to witnesses, whose words are rules to the judges concerning those matters on which they are to deliver their opinion; for it is necessary for the judges to attend to them alone, when there is nothing else existing which can contribute to proof in the matter in question; from which it arises that those who are borne down by evidence in this way meet with injustice when they might have won their cause, and that those who attend to the false witnesses are recorded as unjust and illegal judges, instead of just and legal ones.