Eknath Easwaran's Commentary
The word guru has passed into the English language, but it is often misunderstood. Guru simply means “heavy,” one who is so heavy that he or she can never be shaken. A guru is a person who is so deeply established within himself or herself that no force on earth can affect the complete love they feel for everyone.
It is good for us to remember that the guru, the spiritual teacher, is in every one of us. The outer teacher makes us aware of the teacher within.
We should select a teacher very carefully. We should not get carried away by personal appearance – because we like his hairstyle or her robes. There is a good test of authenticity: does their life accord with what they teach? We have to listen carefully, judge carefully, then make our own decision. Once we make a decision and select a teacher who is suited to our spiritual needs, we should be prepared to be loyal. To the extent we can be loyal to the outer teacher, we are being loyal to ourselves.