Iyengar yoga classes usually start with the teacher chanting the Invocation to Patanjali. The invocation is a form of acknowledging and appreciating Sage Patanjali for his teachings of yoga. Students are encouraged to join in the chanting, but it is totally optional.
Chanting of the invocation connects the teacher to the tradition of yoga teachers from whom they received their knowledge and helps put them in a frame of mind to best teach yoga. The invocation settles the air in the studio, acknowledges the source of the knowledge, and helps the student settle down and prepare to study yoga.
Sage Patanjali penned the ancient Indian heritage of Yoga through his treatise the Yoga Sutras of Patanjali, which is an encompassing study of the subject which consists of just 196 sutras (aphorisms).
The chant, in traditional Sanskrit, is listed below. If you want to chant along with the teacher, you may want to print out this invocation and bring it to class. But remember, this is optional. Sitting quietly and respectfully during the chant is totally acceptable.
Translation of the Invocation:
Let us bow before the noblest of sages Patanjali, Who gave Yoga for serenity and sanctity of mind, Grammar for clarity and purity of speech, and Medicine for perfection of health. Let us prostrate before Patanjali, An incarnation of Adisesa, Whose upper body has a human form Whose arms hold a conch and disc, and Who is crowned by a thousand headed cobra.