The ninth commandment, You shall not bear false witness against your neighbor
(Exodus 20:16), is at issue here. The wicked has no guard over their mouth. Deceptive words flow forth from their mouth. As a result, the life of the neighbour is endangered (cf. Leviticus 19:16). James 3:5–6 also warns on this matter: So also the tongue is a small member, yet it boasts of great things. How great a forest is set ablaze by such a small fire! And the tongue is a fire.
So, keep your tongue in check.
19 “You give your mouth free rein for evil, and your tongue frames deceit.