As per-tradition, before we start any text, we are offering a prayer for the success of study and as the act of gratitude for the opportunity to study. Here is a special prayer for sage pātanjali, not just for us to show our gratitude, but in this prayer itself showing the greatness of him.
योगेन चित्तस्य पदेन वाचां मलं शरीरस्य च वैद्यकेन । Yogena cittasya padena vācām malam śarīrasya ca vaidyakena
योऽपाकरोत् तं प्रवरं मुनीनां पत पतञ्जलिं प्रञ्जलिरानतोऽस्मि ll
Yopākarot tam pravaram munīnā patanjalim pranjalirānatosmi
I am saluting sage patanjali who is excellent among muni. Who removes impurity of the mind by teaching yoga (absorption of the mind), removes impurity of the words by grammar, and removes impurity of the body by Ayurveda.
What is impurity of the mind?
When the mind become the master of me, I am no longer the master of my mind. That is the impurity of the mind.
What is impurity of the words? When a sentence is not properly done grammatically, it will not convey its meaning. Therefore he wrote a commentary on Panini Sutra in Sanskrit literature.
What is impurity of the body? Disease which give affliction to your body. He wrote commentary text on Ayurved.
Yoga Sutra is a text which belong to Yoga darśana (one of the view / school of though) in India. To categorised as a view here, 7 points are there which need to be fulfilled:
Nature of jīva
Nature of jagat
Nature of īsvara
What is human problem
What is the cause of bondage
What is freedom / moksha
Moksha sadhanam / means to be free
6 astika darśna which accept veda (the body of knowledge also known as Hindu scripture, first portion called karmakanda and last portion called vedanta) as means of knowledge. They are:
1. Sangkhya (by kapilamuni)
2. Yoga (by sage patanjali)
3. Nyaya (by gautamamuni) 4. Vaiśesika (by kanadamuni)
5. Pūrvamimamsa (analysis on first part of Veda by jaimini) 6. Uttaramimamsa (analysis on last part of Veda (Vedanta) by vedavyasa)
Similarity between Yoga and Uttaramimamsa:
Accept Veda as means of knowledge
Self / Atma is of the nature of consciousness
Atma is asanggah / ever free from problem
Cause of bondage is confusion between self and non self
For moksha, we need separation of self and non self
Both accept isvara
Different:
For Yoga, Prakrti is real but, we consider Maya is mithya (not exist independently)
For Yoga, Atma is manyfold, but we have only 1 Atma
For Yoga, by practice alone for secession of the mind one will get moksha, for us by cognitive separation, understanding I am the only reality through sravanam (learning the scripture with guidance of teacher), mananam (resolving the doubt), and nididhyasanam (removing the habitual error).
If it is not the same line as our vedanta teaching, why should be learn Yoga Sutra? There is essence in every body of knowledge. The main thing for one to be qualified to study vedanta is adikaritvam (student's qualification), then the teaching of vedanta can be understood. Yoga sastra help us the vedanta student to have a qualified mind sadanacatustayasampannah which is endow with 4 fold qualification which are discrimination, dispassion, mastery over the mind etc, and longing for liberation.