John Gill

For thy mouth uttereth thine iniquity,.... Which was in his heart, and so was an evidence against him, and proved him perverse, and made good the above charges exhibited against him: or "thine iniquity teaches thy mouth" (y); the wickedness that was in his heart prompted his mouth to speak the things he did, see Mat 12:34; and this, as it was an instance of his folly, Pro 15:2; so a proof of his casting off the fear of the Lord; for if that had been before his eyes, he would have bridled his lips, and not uttered all the wickedness of his heart: for he that "bridleth not his tongue, this man's religion is vain", Jam 1:26; and thou choosest the tongue of the crafty; coloured over things under specious pretences of religion and godliness, so that the simple and ignorant took him for a holy good man, when he was at heart an hypocrite; in this light Eliphaz puts Job, as one that walked and talked in craftiness, and was a deceitful worker, and imposed upon men with false glosses and plausible pretences. (y) "docuit iniquitas tua os tuum", V. L. Pagninus, Bolducius; "docebit", Montanus; "docet", Piscator, Cocceius; so Tigurine version.