Sutras 1.27 - 1.28. Sanskrit and mantra-yoga

The following two lines of Yoga Sutras are dedicated to mantras and power of the sound.

तस्य वाचकः प्रणवः ॥२७॥

1.27. tasya vācakaḥ praṇavaḥ

तज्जपस्तदर्थभावनम् ॥२८॥

1.28. tajjapastadarthabhāvanam 

Sutras 27 and 28 tell that “the expression of that (Isvara) is OM (pranava)” and “the repetition of it (Om) in one mind’s eye allows one to experience it (the Isvara)”. Without getting into specifics of what the Om-sound means let us raise a more important question: why do mantras generally exist and how do they work?

Sutra 1.25. Ishvara and the world tree. The metaphysics of plato

The line 25 of Yoga Sutras compares Ishvara with a seed that contains omniscience (sarva-jnana-bidja):

तत्र निरतिशयं सार्वज्ञबीजम् ॥ २५॥

1. 25. tatra niratiśayaṃ sārva-jña-bījam 

1. 25. In Him [Ishvara] is the complete manifestation of the seed of omniscience. [Engl. transl. by Swami Satchidananda – translator’s note].

This happens to be in a remarkable manner aligned with an amazing line from Katha Upanishad: