Proverbs 27:9 - Matthew Poole's English Annotations on the Holy Bible

Rejoice the heart, by increasing and comforting the spirits. No less grateful and pleasant is the company and conversation of a true friend, in respect of his good and faithful counsel, which comes from his very heart and soul, and contains his most inward and serious thoughts, whereas deceitful persons give such counsels, not as they think to be best, but as most serve their lusts or designs.