That which I see not, teach thou me - That is, in regard to my errors and sins. No prayer could be more appropriate than this. It is language becoming every one who is afflicted, and who does not see clearly the reason why it is done. The sense is, that with a full belief that he is liable to error and sin, that he has a wicked and deceitful heart, and that God never afflicts without reason, he should go to him and ask him to show him "why" he has afflicted him. He should not complain or repine; he should not accuse God of injustice or partiality; he should not attempt to cloak his offences, but should go and entreat him to make him acquainted with the sins of heart and life which have led to these calamities. Then only will he be in a state of mind in which he will be likely to be profited by trials.
If I have done iniquity, I will do no more - Admitting the possibility that he had erred. Who is there that cannot appropriately use this language when he is afflicted?

That which I see not - "What I do not know, teach thou me; wherein I have done iniquity, I will do so no more."

(a) [That which] I see not teach thou me: if I have done iniquity, I will do no more.
(a) Thus Elihu speaks in the person of God, as it were mocking Job, because he would be wiser than God.

That which I see not teach thou me,.... Which may be understood either of the chastisements of God, and his dealings with his people in a providential way, and of the design and use of them, which are sometimes unsearchable, and at most but a part of them only seen and known; it is meet to say to God, it is but a small part and portion of thy ways that is known by me; I can see but little into them: teach me more of thy mind and will in them, or else of sins and transgressions, the cause of chastisement; it is proper for an afflicted man to say unto God, I am conscious to myself of many sinful failings and infirmities, but there may be secret sins committed by me which have escaped my notice and observation; point them out to me, that I may be humbled for them, and make a free confession of them;
if I have done iniquity, I will do no more; that is, if I have committed any capital crime, any foul offence or gross enormity, for otherwise no man lives without sin, I sincerely repent of it, and will take care for the future, through divine grace, to do so no more.

(Job 10:2; Psalm 32:8; Psalm 19:12; Psalm 139:23-24).
no more-- (Proverbs 28:13; Ephesians 4:22).

That - The secret sins which I cannot discover, manifest thou to me.