The Bhagavad-gītā is one of the popular literatures which are generally heard, chanted, repeated, etc., by the people in general, but in spite of such hearing, etc., sometimes it is experienced that the performer of such devotional service does not see the Lord face to face. The reason is that the first item, śravaṇa, is very important. If hearing is from the right sources, it acts very quickly. Generally people hear from unauthorized persons. Such unauthorized persons may be very learned by academic qualifications, but because they do not follow the principles of devotional service, hearing from them becomes a sheer waste of time. Sometimes the texts are interpreted fashionably to suit their own purposes. Therefore, first one should select a competent and bona fide speaker and then hear from him. When the hearing process is perfect and complete, the other processes become automatically perfect in their own way.

SB 1.8.36 purport