Those who are patient have great understanding, but the quick-tempered display folly. (NIV)
He who is slow to anger has great understanding, but he who is hasty of spirit exposes and exalts his folly. [Prov. 16:32; James 1:19.] (AMP)
He that is slow to wrath is of great understanding: but he that is hasty of spirit exalteth folly. (KJV)