Listening
As a manager, a person must learn to be patient, loving, and above all, learn to listen to others until they have finished. This is, in my experience, the most important attribute that a human being must develop. I pray that you will do so. Speaking is not so important. The ability to listen carefully, and patiently, is.
Taken from the book "The Spider's Web, Vol. 3", Chapter "Attitude", pg. 201, by Revered Chariji