All flesh shall perish together - If God chose, he would have a right to cut down the whole race. How then shall people complain of the loss of health, comforts, and friends, and presume to arraign God as if he were unjust?
Matthew Henry
Concise Bible Commentary
Elihu had showed Job, that God meant him no hurt by afflicting him, but intended his spiritual benefit. Here he shows, that God did him no wrong by afflicting him. If the former did not satisfy him, this ought to silence him. God cannot do wickedness, nor the Almighty commit wrong. If services now go unrewarded, and sins now go unpunished, yet there is a day coming, when God will fully render to every man according to his works. Further, though the believer's final condemnation is done away through the Saviour's ransom, yet he has merited worse than any outward afflictions; so that no wrong is done to him, however he may be tried.
SDA Bible Commentary (limited)
Volume 1-7
15. All flesh. Elihu sets forth God’s sovereign power. If God should so will, He could destroy man in a moment. No one can deny God the right to do so. Man has no claim on life. Being such a sovereign, God reserves the right to afflict His creatures if He sees best.