mouth

Proverbs 10:20, 21, 32
The tongue of the righteous is choice silver, but the heart of the wicked has little worth. . . .

Proverbs 13:14
The teaching of the wise is a fountain of life, turning one from the snares of death.

Proverbs 15:7
The lips of the wise spread knowledge, but not so the hearts of fools.

Proverbs 16:22-24
Understanding is a fountain of life to its possessor, but the discipline of fools is folly. . . .

Proverbs 18:4
The words of a man's mouth are deep waters; the fountain of wisdom is a bubbling brook.

Proverbs 20:15
There is gold and abundance of rubies, but lips of knowledge are a rare treasure.

Psalm 37:30, 31
The mouth of the righteous man utters wisdom, and his tongue speaks justice. . . .

Ephesians 4:29
Let no unwholesome talk come out of your mouths, but only what is helpful for building up the one in need and bringing grace to those who listen.

but

Psalm 107:42
The upright see and rejoice, and all iniquity shuts its mouth.

Ecclesiastes 10:12-14
The words of a wise man's mouth are gracious, but the lips of a fool consume him. . . .

Matthew 12:34-37
You brood of vipers, how can you who are evil say anything good? For out of the overflow of the heart, the mouth speaks. . . .

James 3:5-8
In the same way, the tongue is a small part of the body, but it boasts of great things. Consider how small a spark sets a great forest ablaze. . . .