Ecclesiastes 10:12

The words of a wise man's mouth are gracious, But the lips of a fool shall swallow him up;

Surrounding context

10:11 A serpent may bite when it is not charmed; The babbler is no different.

10:12 The words of a wise man's mouth are gracious, But the lips of a fool shall swallow him up;

10:13 The words of his mouth begin with foolishness, And the end of his talk is raving madness.