Based on the verses from Dnyaneshwar Maharaj cited in the text, what is the prescribed method for attaining true knowledge?

The preface in Chapter 0 begins by quoting Lord Samarth Sadguru Dnyaneshwar Maharaj to explain the path to knowledge. According to these verses, if you wish to bring beautiful knowledge into your mind, the key is to serve the saints with your entire being. This service is the 'doorway' to the 'treasure of knowledge.' The method requires a complete surrender at their feet with your body, mind, and soul, performing all service without ego. When this is done, the saints will impart what you have asked for, leading to an enlightenment of the heart that ensures no doubts can arise. This selfless service is presented as the fundamental prerequisite for spiritual wisdom.