Proverbs 27:19 - Coke's Commentary on the Holy Bible

As in water, &c.— Dr. Grey says, this should be rendered, As the water showeth the face to the face, so doth the heart the man to the man. The meaning is, that a man may know what character he deserves, as well by looking into his own heart, as he can tell what sort of a face he has by looking upon the water. Houbigant renders it, As faces are like faces, so the heart of one man to another.