目は口ほどに物を言う (めはくちほどにものをいう): one can say more with a look than with ten thousand words; the eyes cannot belie one's true thoughts; the eyes are the windows to the soul

one can say more with a look than with ten thousand words; the eyes cannot belie one's true thoughts; the eyes are the windows to the soul

The eyes say as much as the mouth does. Said when someone's face has already answered the question they are politely declining to answer.

A Japanese proverb (ことわざ)