Yo'vipastho jñāhetuśca योऽविपस्थो ज्ञाहेतुश्च॥ (sūtra III.29)

The yogi who appears like Śiva (sūtra III.25), by practicing austerities attains competence to teach others. Therefore, this sūtra says,

yaḥ - who; avipasthaḥ – established; jñā – knowledge; hetuḥ – means; ca – indeed.

The yogi who established himself beyond the realms of karmendriya-s and jñānendriya-s and who is always submerged in pure Divine consciousness becomes eligible to impart spiritual knowledge to others. The organs of action and cognition cannot influence him as they are under his command and control. On the contrary, an ignorant man is influenced and induced by senses, making him succumb to sensual pleasures. This is the significant difference between a man leading a mundane life, unwilling to explore the Spirit within and a yogi who always stays submerged in the blissful state of Supreme consciousness by practicing austerities. The one who is afflicted with sensory influences cannot continue to remain always in Supreme consciousness. Since such a person is not totally refined and purified, he cannot be a true master. Unless a spiritual master is a realised person, he cannot effectively lead others to spiritual illumination. This aphorism says that one can be a spiritual master only if he is a Self-realised person. He has not attained this stage with ease. He has crossed several hurdles while controlling and focussing his mind. Spiritual attainment is not an easy path to pursue for those who do not have the necessary will power.