Proverbs 17:27
"He that hath knowledge spareth his words: and a man of understanding is of an excellent spirit."
Cross References (ranked by relevance)
And the fruit of righteousness is sown in peace of them that make peace.
Wherefore, my beloved brethren, let every man be swift to hear, slow to speak, slow to wrath:
He that is slow to wrath is of great understanding: but he that is hasty of spirit exalteth folly.
In the multitude of words there wanteth not sin: but he that refraineth his lips is wise.
The heart of the righteous studieth to answer: but the mouth of the wicked poureth out evil things.
For in many things we offend all. If any man offend not in word, the same is a perfect man, and able also to bridle the whole body.
The words of wise men are heard in quiet more than the cry of him that ruleth among fools.
He that is slow to anger is better than the mighty; and he that ruleth his spirit than he that taketh a city.