Contradiction with Psalm 33:17
This verse says that a horse is a vain thing for safety, contrasting with the notion of strength highlighted in Job 39:20.
Psalm 33:17: An horse [is] a vain thing for safety: neither shall he deliver [any] by his great strength.
Contradiction with Proverbs 21:31
This verse suggests that safety is of the Lord, not dependent on the horse's strength, contrary to the strength implication in Job 39:20.
Proverbs 21:31: The horse [is] prepared against the day of battle: but safety [is] of the LORD. [safety: or, victory]
Contradiction with Ecclesiastes 9:11
This verse indicates that the race is not to the swift, countering the swiftness implied in Job 39:20 about the horse's capabilities.
Ecclesiastes 9:11: I returned, and saw under the sun, that the race [is] not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favour to men of skill; but time and chance happeneth to them all.