[He that] speaketh truth showeth forth righteousness
He that "blows" or "breathes out truth" F4, as the word signifies; that utters it freely and fully without any hesitation; that speaks nothing but truth, and speaks out the whole truth without any reserve; such a man upon every occasion will declare that which is just and right, and show himself to be an honest and upright man; he that uses himself to speak truth in common conversation, will, in a court of judicature, whether upon his oath or not, testify that which is just and the real matter of fact; there is a connection between truth and righteousness, for though they are distinct things they go together, what is true is just, and what is just is true; so he that speaks the truth of the Gospel, or is a faithful preacher of it, will show forth righteousness, what is the righteousness of the law, and what is the righteousness of faith; how insufficient a man's own righteousness is to justify him in the sight of God; the necessity of the righteousness of Christ, how free and full, excellent and glorious, suitable and useful it is, ( Romans 1:17 ) ; but a false witness deceit;
that is, one that is used to lying, when he is called to give testimony upon any affair in judgment, he will declare that which is false and deceitful, having no regard to truth and justice. So a false teacher, instead of showing men the insufficiency of their own righteousness, and directing them to the righteousness of Christ for justification, will utter deceitful doctrine, and build up their hopes upon the sandy and deceitful foundation of their own works; as Popish teachers, and such as verge towards them.