Dhyana Yoga (Atma Samyama Yoga)

उद्धरेदात्मनात्मानं नात्मानमवसादयेत्। आत्मैव ह्यात्मनो बन्धुरात्मैव रिपुरात्मनः॥

One must elevate oneself by one's own mind, not degrade oneself. The mind is indeed the greatest friend of the conditioned soul, and the mind can also be its greatest enemy.

यतो यतो निश्चरति मनश्चञ्चलमस्थिरम्। ततस्ततो नियम्यैतदात्मन्येव वशं नयेत्॥

From wherever the fickle and unsteady mind wanders away due to its restless nature, one must restrain it and bring it back again and again under the control of the Self.