In ancient Indian tradition, a ceremony is performed prior to instruction. This is known as a guru puja. The ceremony recognizes the tradition from which the teaching comes. Such a puja typically has three parts: the lineage, offerings you would make to a guest in your home, and a celebration of the wisdom. It also serves to raise the consciousness of the teacher prior to instruction.
At the beginning of the guru puja is an invocation:
Apavitrah Pavitro va
Sarva Vasthan Gatopi va
Yah Smaret Pundari-kaksham
Sa Bahya-Bhyantarah Shuchih
“Whether pure or impure, whether all places are permeated by purity or impurity,
whoever opens himself to the expanded vision of unbounded awareness gains inner and outer purity.”
I explored this process in The Importance of Actual Yoga.