Albert Barnes Commentary Job 35:7

"If thou be righteous, what givest thou him? Or what receiveth he of thy hand?" — Job 35:7 (ASV)

If thou be righteous, what givest thou him? - This is substantially the same sentiment as in the previous verses. It is that God is supreme and independent. He does not desire such benefits from the services of his friends and is not so dependent on them as to be induced to interpose in their favor in any way beyond what is strictly proper.

Therefore, it is to be presumed that he will deal with them according to what is right. And since it is right that they should experience proofs of his favor, it followed that there would be advantage in serving him and in being delivered from sin, and that it would be better to be holy than to lead a life of transgression. This reasoning seems to be somewhat abstract, but it is correct, and is as sound now as it was in the time of Elihu.

There is no reason why God should not treat people according to their character. He is not so under obligations to his friends and does not have such cause to dread his foes; he does not derive so much benefit from the one, or receive such injury from the other, that he is under any inducement to swerve from strict justice; and it follows, therefore, that where there ought to be reward there will be, where there ought to be punishment there will be, and consequently, that there is an advantage in being righteous.