Too much plenty makes mouth dainty

In a discreet man's mouth, a public thing is private

When you speak to a man, look on his eyes; when he speaks to thee, look on his mouth.

Mary's mouth costs her nothing, for she never opens it but at others expense

Speak and speed: the close mouth catches no flies.

The heart of a fool is in his mouth, but the mouth of the wise man is in his heart