If thou sinnest, what doest thou against him? - This should not be interpreted as designed to justify sin, or as saying that there is no evil in it, or that God does not regard it. That is not the point or scope of the remark of Elihu. His object is to show that God is not influenced in his treatment of his creatures as people are in their treatment of each other. He has no "interest" in being partial, or in treating them otherwise than they deserve. If they sin against him his happiness is not so marred that he is under any inducement to interpose "by passion," or in any other way than that which is "right."

If thou sinnest - God is not benefited by thy righteousness, nor injured by thy iniquity, howsoever multiplied it may be.

If thou sinnest, what doest thou (d) against him? or [if] thy transgressions be multiplied, what doest thou unto him?
(d) Neither does your sin hurt God, nor your justice profit him: for he will be glorified without you.

If thou sinnest, what dost thou against him?.... Sin is expressly said to be against God, Psalm 51:4; it is contrary to his nature, as any opposites can be to each other: it is against his law, a breach and violation of it; and so against his supreme legislative power and authority, and a contempt of it; it is what he is angry with and is provoked by, being what he hates and abhors, and is abominable in his sight. But then he cannot be supposed to be so affected with it to be ruffled and discomposed, or his peace be disturbed, and his happiness in the least broke in upon; for affections are only attributed to him after the manner of men; much less is he so affected hereby as to be hurt or in danger of being destroyed, nor even of being dethroned: men can no more reach him by any hostile action of theirs, such as sin is, than they can reach the sun and stop its course, lessen its light or pluck it from its orbit. Or, "what canst thou work for him?" as Mr. Broughton; by way of atonement or satisfaction for sin? Nothing at all; see Job 7:20; but the other sense is best;
or if thy transgressions be multiplied, what dost thou unto him? As he is not hurt by a slight single sin, a failing or infirmity, an error or mistake, common to men, as the preceding word may signify; so not by greater sins, presumptuous ones, gross enormities, rebellions against God, overt acts of treason against the Almighty, and these multiplied and heaped up even unto heaven; for though by these the name of God is profaned and blasphemed, and he is dishonoured and despised, and his manifestative glory is eclipsed, or he has not the honour given him that is due unto him; yet his essential glory is untarnished, unsullied, and unhurt, no more than the sun by an eclipse; he is the same without any variableness or shadow of turning, as well as is over all blessed for ever. And, indeed, his manifestative glory in many instances receives a lustre, through his power, wisdom, and goodness, overruling the sins of men for the display of it; as the fall of the first Adam made way for the sending of Christ the Saviour, in which God has shown forth the exceeding riches of his grace; and as his mercy and grace are displayed in the pardon of sin, and his power and justice in the punishment of sin and sinners; and his patience and longsuffering in bearing with them.

what doest--how canst thou affect Him?
unto him--that can hurt Him? (Jeremiah 7:19; Proverbs 8:36).