Sutra 2.1 "The Yoga of action consists of austerity, self-study and surrender to the Supreme Being."
I've been looking forward to reading my way through book 2 of the Yoga Sutras because it encompasses the sutras that directly relate to the physical "active" practices of yoga. Interestingly, both commentary from Iyengar and Maehle suggest that, of the 4 books in the Yoga Sutra, this one is most applicable to beginners. They describe beginners as those who still have work to do on the outward practices (the limbs before meditation). I'm definitely a beginner.
It also interests me that the first sutra in a book for beginners includes words like "austerity" and "surrender". They both suggest to me that this "Yoga of action" is something that is going to involve some discomfort! Beryl Bender Birch likes to translate "Isvara" (Supreme Being) as "aware presence" or "present moment". I like that translation as it gives this sutra a broader meaning. It suggests that yoga practice is going to involve surrender to what is larger than myself in any given present moment.
Beryl also likes to point out that friction, irritation and general mental suffering arise when we push against the present moment rather than surrendering to it. She's a wise person!...now if only that wasn't so hard! I've actually gone so far as to throw a kicking and screaming temper tantrum in asana practice...this was years ago...it was only once...no one was there to see it. :)
I had tweaked something in my back while at work after several days spent heaving around bags or fertilizer. I was very frustrated that I could not do my "full practice". The result of said tantrum?...a bruised foot.
The moments when I have moved toward surrender have been worth the discomfort every time. That said, I'm not sure it gets any easier to accept that the world is larger than my tiny sphere in it. Ego can be so loud! ...and that I suppose is the reason that Book 2 of the Yoga Sutra is the "Book on Practice". "Practice and all is coming" -S.K.P.J. ...but maybe not all is coming in this lifetime...