But oh that God would speak, and open his lips against thee;

Wesley's Notes

11:5 Speak - Plead with thee according to thy desire: he would soon put thee to silence. We are commonly ready with great assurance to interest God in our quarrels. But they are not always in the right, who are most forward, to appeal to his judgment, and prejudge it against their antagonists.

Matthew Henry's Concise Commentary

11:1-6 Zophar attacked Job with great vehemence. He represented him as a man that loved to hear himself speak, though he could say nothing to the purpose, and as a man that maintained falsehoods. He desired God would show Job that less punishment was exacted than he deserved. We are ready, with much assurance, to call God to act in our quarrels, and to think that if he would but speak, he would take our part. We ought to leave all disputes to the judgment of God, which we are sure is according to truth; but those are not always right who are most forward to appeal to the Divine judgment.