Proverbs 27:19 - Ellicott's Commentary On The Whole Bible

So the heart of man (answereth) to man. — What is in our own hearts we find in others also. Whatever are the distinguishing features of our own characters we discover and elicit the same in others. The merciful, the generous, the devout, the pure, recognise the same qualities in others, and themselves feel and receive sympathy from such persons. So the evil, too, find themselves in harmony with those of like disposition.