Job 11:4

For thou hast said, My doctrine [is] pure, and I am clean in thine eyes.

Ver. 4. For thou hast said] Thou hast confidently affirmed; and this he makes to be a loud lie, and not an idle word only. But where and when had Job said it? Did not Zophar openly play the sophister, so interpreting what Job had spoken, Job 6:10; Job 9:22; Job 10:7, in defence of his innocence, as if Job had maintained that he was free from all sin; whereas, notwithstanding, he had very often witnessed and confessed himself to be a sinner, insomuch as that albeit he were without sin, yet he could not be accounted clear and pure in the sight of God? But Zophar took these for good words only, and was therefore so sharply set against him. So Cyril and Theodoret mistook one another, and objected heresy mutually; when afterwards it appeared that they were both of one judgment. Charity would have taught Zophar to have taken Job in a better sense, and to have said of him, as Cruciger did of Luther, eum commodius sentire quam loquitur dum effervescit, that he held right, though in his heat he spake not so fitly as might be wished. Good men's words are reverenter glossanda (as one said of the laws), to have a reverent gloss put upon them, and not, by a spiritual unmannerliness, to be taken with the left hand, when they might and ought to be taken with the right.

My doctrine is pure] Clear as crystal, transparent as a crystal glass with a light in the midst; you may see through it, and find no flaw or filth in it. Job was no professed preacher, yet he had "not concealed the words of the Holy One," Job 6:10. As he had received the knowledge of the truth from parents and teachers (the word here rendered doctrine comes from a root that signifieth to receive), so he had freely and purely imparted it to others, commending it unto them as sound and sincere, and therefore well worthy of all acceptation. But that which troubled Zophar and his two fellows was, that Job should affirm that God did afflict good men in this world as heavily as bad men, which yet was an irrefragable truth, such as Job resolved to live and die in.

And I am clean in thine eyes] i.e. I am not sinless, but sincere and upright, no hypocrite (as you have charged me), no worker of iniquity, but one that would be cleansed from all filthiness of flesh and spirit, and do, by the daily practice of mortification, purify myself as God is pure. More than this Job said not, though Zophar thought he did, and therefore wisheth in the next words that God himself would convince him of his error.