Whenever you talk to other people, never speak ill of others. You should avoid even hearing criticism of other people. If you have to hear criticism of others, quietly hear it but never join in. Take special note of this. If you criticize others or hear others being criticized, your mind will be polluted and it will go down. It will then be difficult for you to love God.
(p.208, Letters for Spiritual Seekers, Letters of Swami Shivananda)