God is omniscient—when setting up the human justice system, he knew man would make false oaths and bear false witnessing or raise a false report against his neighbor, friend, or family member. Judges and juries were set in place to safeguard against false reports along with each witness examined separately to minimize collaboration and escape detection of falsified testimony.
Don’t you see that whatever enters the mouth goes into the stomach and then out of the body? But the things that come out of the mouth come from the heart, and these things make a man unclean. For out of the heart comes evil thoughts, murder, adultery, sexual immorality, theft, false testimony, slander.