When that is accomplished, the seer abides in its own true nature / Tada drastuh svarupe vasthanam
The Yoga Sutras - Chapter 1, Sutra #3
As stated in the previous sutra, yoga means the cessation of thoughts for the sole purpose of allowing the soul to abide in its own nature. According to yoga philosophy, the nature of the soul is pure consciousness, just as the nature of the sun is and has always been to shine.
To illustrate the nature of the soul as pure consciousness alone, devoid of content, and the relationship between consciousness and mind, the Hindu philosophy turns to the example of a pure transparent crystal (consciousness) and a red flower (mind, ego, thoughts). Thus, when a red flower is placed next to a crystal, the color of the flower is reflected in the crystal, and the crystal itself appears red. However, the nature of the crystal is not red, it is not influenced or altered by the flower, and it does not disappear when the flower is removed. In the same way, consciousness reflects external objects and internal thoughts but is never affected by them.
So, the soul as pure consciousness, according to the Yoga Sutras, is an autonomous entity separable from the mind and thoughts. The soul retains its pure nature of awareness when detached from the mind and ego through the practice of yoga.