Proverbs 14:29 in the King James Version
He that is slow to wrath is of great understanding: but he that is hasty of spirit exalteth folly.
Context
28 In the multitude of people is the king’s glory, but in the lack of people is the destruction of the prince.
29 He who is slow to anger has great understanding, but he who has a quick temper displays folly.
30 The life of the body is a heart at peace, but envy rots the bones.