A competent and self-confident person is incapable of jealousy in anything. Jealousy is invariably a symptom of neurotic insecurity.
Source: Time Enough for Love (1973) by Robert A. Heinlein; Intermission: Excerpts from the Notebooks of Lazarus Long, page: 250.
True confidence has no room for jealously and envy. When you know you are great, you have no reason to hate.
True confidence leaves no room for jealousy. When you know your are great, you have no need to hate.
Source: Sophia Loren Arneson, Krystin; Gustashaw, Megan (2011). “25 of the Best Fashion Quotes of All Time”. Glamour. Retrieved January 22, 2013.