Albert Barnes Commentary Job 15:8

"Hast thou heard the secret counsel of God? And dost thou limit wisdom to thyself?" — Job 15:8 (ASV)

Have you heard the secret of God? - literally, “in the secret of God have you heard” - הסוד hasôd. The word rendered “secret” (סוד sôd) means properly a “couch” or “cushion,” on which one reclines—whether for sleep, at a table, or as a divan. Hence, it means a divan, or circle of persons sitting together for familiar conversation (Jeremiah 6:11; Jeremiah 15:17); or of judges, counselors, or advisers for consultation, as the word “divan” is now used in Eastern countries (Psalms 89:7; Jeremiah 33:18).

Then it means any consultation, counsel, familiar conversation, or intimacy (Psalms 55:14; Proverbs 15:22). Here God is represented in language characteristic of the East as seated in a “divan,” or council of state, where deliberation occurs about the concerns of His government, and important questions are debated and decided. Eliphaz then asks Job whether he had been admitted to that council and had heard those deliberations. He further questions whether, if Job had not, he was qualified to pronounce as he had done on the plans and purposes of the Almighty.

And do you restrain wisdom to yourself? - Having obtained the secret of that council, are you now keeping it wholly to yourself—as a prime minister might be supposed to keep the purposes resolved on in the divan? “Have you listened in the council of yahweh, and do you now reserve all wisdom to yourself?”