Don't demonstrate frivolous jealousy at your friends' success. If an acquaintance is wearing a new tie or a new blouse that you yourself would like, don't capriciously point out its shortcomings to him or her. "Yes, it's nice, but it has a stain on it." That will only serve to irritate him and won't help either his or your practice.
From Training the Mind & Cultivating Loving-Kindness by Chogyam Trungpa , copyright 1993 by Diana Mukpo.
(Official Chogyam Trungpa Website)
Published by arrangement with Shambhala Publications, Inc., Boston.
This site provides an on-line database of commentaries on the Tibetan Buddhist meditation practices of lojong (Mind Training) and tonglen.