Contradiction with Job 7:11
Job expresses his intention to speak in the anguish of his spirit, whereas in Job 21:4 he questions if his complaint is to man, implying the insignificance of human complaint to God.
Job 7:11: Therefore I will not refrain my mouth; I will speak in the anguish of my spirit; I will complain in the bitterness of my soul.
Contradiction with Philippians 2:14
Encourages doing all things without murmuring and disputing, which contrasts with Job's expression of complaint in Job 21:4.
Philippians 2:14: Do all things without murmurings and disputings: