If thou hast anything to say, answer me - In the previous verse, Elihu had asked that Job would hear all that he had to say. Yet here, in view of what he had said, he asks of him that if there were any thing from which he dissented, he would now express his dissent. We may suppose that he paused at this part of his speech, and as what he had said related particularly to Job, he felt that it was proper that he should have an opportunity to reply.
For I desire to justify thee - I would do you justice. I would not pervert what you have said, or attribute to you any wrong opinions or any improper motives Perhaps there may be included also a wish to vindicate him, if he possibly could. He did not desire to dispute for the sake of disputing, or to blame him if he could avoid it, but his aim was the truth; and if he could, he wished to vindicate the character of Job from the aspersions which had been cast upon it.

If thou hast any thing to say - If thou hast any objection to make against what I have already stated, now answer, now speak freely; for it is my desire that thou shouldst stand clear of all charges.

If thou hast any (y) thing to say, answer me: speak, for I desire to (z) justify thee.
(y) If you doubt anything, or see opportunity to speak against it.
(z) That is, to show you, in which mans justification consists.

If thou hast anything to say, answer me,.... Any thing to object to what he had delivered, or any answer to return to what he had charged him with:
speak, for I desire to justify thee. Elihu was a fair antagonist, and gave free liberty, time and space, to make whatsoever reply he thought fit, and which he should patiently and attentively hear: his view was not victory, but that truth might come out, and take place and prevail, having nothing more at heart than Job's good; and could wish it would appear that he was in all respects a just man, and even in that in which he thought he was not just; but could he fairly acquit himself it would be a pleasure to him.

justify--to do thee justice; and, if I can, consistently with it, to declare thee innocent. At Job 33:33 Elihu pauses for a reply; then proceeds in Job 34:1.