Will ye speak wickedly for God? - That is, will you maintain unjust principles with a view to honor or to vindicate God? Job refers doubtless to the positions which they had defended in regard to the divine administration - principles which he regarded as unjust, though they had employed them professedly in vindicating God. The sense is, that unjust principles ought not to be advanced to vindicate God. The great cause of truth and justice should always be maintained, and even in attempting to vindicate the divine administration, we ought to make use of no arguments which are not based on that which is right and true. Job means to reproach his friends with having, in their professed vindication of God, advanced sentiments which were at war with truth and justice, and which were full of fallacy and sophistry. And is this never done now? Are sophistical arguments never employed in attempting to vindicate the divine government? Do we never state principles in regard to him which we should esteem to be unjust and dishonorable if applied to man? Do not good people sometimes feel that that government must be defended at all events; and when they can see no reason for the divine dealings, do they not make attempts at vindicating them, which are merely designed to throw dust in the eyes of an opponent, and which are known to be sophistical in their nature? It is wrong to employ a sophistical argument on any subject; and in reasoning on the divine character and dealings, when we come, as we often do, to points which we cannot understand, it is best to confess it. God asks no weak or sophistical argument in his defense; still less can he be pleased with an argument, though in defense of his government, which is based on unjust principles.
And talk deceitfully for him - Use fallacies and sophisms in attempting to vindicate him. Everything in speaking of God, should be true, pure, and sound. Every argument should be free from any appearance of sophism, and should be such as will bear the test of the most thorough examination. No honor is done to God by sophistical arguments, nor can he be pleased when such arguments are employed even to vindicate and honor his character.

Will ye speak wickedly for God? - In order to support your own cause, in contradiction to the evidence which the whole of my life bears to the uprightness of my heart, will ye continue to assert that God could not thus afflict me, unless flagrant iniquity were found in my ways; for it is on this ground alone that ye pretend to vindicate the providence of God. Thus ye tell lies for God's sake, and thus ye wickedly contend for your Maker.

Will ye speak (c) wickedly for God? and talk deceitfully for him?
(c) He condemns their zeal, who did not have knowledge, nor regarded they to comfort him, but always granted on God's justice, as though it was not evidently seen in Job, unless they had undertaken the probation of it.

Will you speak wickedly for God?.... As he suggests they did; they spoke for God, and pleaded for the honour of his justice, by asserting he did not afflict good men, which they thought was contrary to his justice; but: then, at the same time, they spoke wickedly of Job, that he being afflicted of God was a bad man, and an hypocrite; and this was speaking wickedly for God, to vindicate his justice at the expense of his character, which there was no need to do; and showed that they were poor advocates for God, since they might have vindicated the honour of his justice, and yet allowed that he afflicted good men, and that Job was such an one:
and talk deceitfully for him? or tell lies for him, namely, those just mentioned, that only wicked men, and not good men, were afflicted by him, and that Job was a bad man, and an hypocrite.

deceitfully--use fallacies to vindicate God in His dealings; as if the end justified the means. Their "deceitfulness" for God, against Job, was that they asserted he was a sinner, because he was a sufferer.

7 Will ye speak what is wrong for God,
And speak what is deceitful for Him?
8 Will ye be partial for Him,
Or will ye play the part of God's advocates?
9 Would it be pleasant if He should search you out,
Or can ye jest with Him, as one jesteth with men?
10 He will surely expose you
If ye secretly act with partiality.
11 Will not His majesty confound you,
And His fear fall upon you?
Their advocacy of God - this is the thought of this strophe - is an injustice to Job, and an evil service rendered to God, which cannot escape undisguised punishment from Him. They set themselves up as God's advocates (לאל ריב, like לבּעל ריב, Judges 6:31), and at the same time accept His person, accipiunt (as in acceptus = gratus), or lift it up, i.e., favour, or give preference to, His person, viz., at the expense of the truth: they are partial in His favour, as they are twice reminded and given to understand by the fut. energicum תּשּׂאוּן. The addition of בּסּתר (Job 13:10) implies that they conceal their better knowledge by the assumption of an earnest tone and bearing, expressive of the strongest conviction that they are in the right. They know that Job is not a flagrant sinner; nevertheless they deceive themselves with the idea that he is, and by reason of this delusion they take up the cause of God against him. Such perversion of the truth in majorem Dei gloriam is an abomination to God. When He searches them, His advocates, out (חקר, as Prov.Job 28:11), they will become conscious of it; or will God be mocked, as one mocketh mortal men? Comp. Galatians 6:7 for a similar thought. חתל is inf. absol. after the form תּללּ, and תּהתלּוּ is also to be derived from תּללּ, and is fut. Hiph., the preformative not being syncopated, for תּתלּוּ (Ges. 53, rem. 7); not Piel, from התל (as 1-Kings 18:27), with the doubling of the middle radical resolved (Olsh. in his Lehrb. S. 577). God is not pleased with λατρεία (John 16:2) which gives the honour to Him, but not to truth, such ζῆλος Θεοῦ ἀλλ ̓ ου ̓ κατ ̓ ἐπίγνωσιν (Romans 10:2), such advocacy contrary to one's better knowledge and conscience, in which the end is thought to sanctify the means. Such advocacy must be put to shame and confounded when He who needs no concealment of the truth for His justification is manifest in His שׂאת, i.e., not: in the kindling of His wrath (after Judges 20:38; Isaiah 30:27), but: in His exaltation (correctly by Ralbag: התנשׂאותו ורוממותו), and by His direct influence brings all untruth to light. It is the boldest thought imaginable, that one dare not have respect even to the person of God when one is obliged to lie to one's self. And still it is also self-evident. For God and truth can never be antagonistic.