Yoga sutra 2.20
draṣṭā dṛśi-mātraḥ śuddhaḥ-api pratyaya-anu-paśyaḥ
The “Seer” can only observe, and although the “Seer” is pure, it observes through the content of the mind
In the two previous sutra-s Patanjali discussed the “seeable” i.e. the field of observation (the world as you perceive it).
Here, Patanjali addresses the “Seer” (the silent witness). Since there is a field of observation, there is an observer. This observer - the “Seer” (draṣṭā) – is pure/flawless (api) and unchangeable (śuddhaḥ). There is no work to be done in this regard. The practice of yoga addresses that part of you that is constantly changing – the mind. The “Seer” is thus in the same position as someone looking at the world with flawed vision. Purification of your mind, therefore, is the only way to properly see.
Damian Cadman-Jones is an authorised teacher of Prana Vashya Yoga™