Wow! I have been reading Job and his friends telling him how he must have done something bad and he was being judged because everything was taken away from him, and how Job was justifying himself because he was righteous in "his own eyes" (don't we do that!), and Elihu was upset because he was justifying himself instead of God.
He had waited to speak because he was younger than them.
Elihu condemns Job's self-righteousness. God does His awesome mighty works, the rain clouds, He breathes on water and it becomes frozen.
God will not listen to empty talk.