यत्रोपरमते चित्तं निरुद्धं योगसेवया ।
यत्र चैवात्मनात्मानं पश्यन्नात्मनि तुष्यति ।। ६.२० ।।

सुखमात्यन्तिकं यत्तद्बुद्धिग्राह्यमतीन्द्रियम् ।
वेत्ति यत्र न चैवायं स्थितश्चलति तत्त्वतः ।। ६.२१ ।।

yatroparamate cittaṁ niruddhaṁ yoga-sevayā |
yatra caivātmanātmānaṁ paśyann-ātmani tuṣyati || 6.20 ||

sukham-ātyantikaṁ yat-tad-buddhi-grāhyam-atīndriyam |
vetti yatra na caivāyaṁ sthitaś-calati tattvataḥ || 6.21 ||

Audio-BG-6.20

Audio-BG-6.21

In the next two verses Krishna pictures how great, redeeming and fulfilling such an inwardly absorbed state of the yogic mind is:

When the mind is restrained and sublimated by yoga-sadhana, particularly by this kind of meditative absorptional effort, the seeker will reach a state in which he will derive the perception of the Self. That perception, involving nothing second, external or otherwise, will be by him of himself. It is not a sensory perception wherein the perceiving senses apprehend the perceivable object, implying in the process a clear distinction and distance between the two – the perceiver and the perceived. Here it is a process of the mind seeing itself, the meditator perceiving himself.

Krishna says that such an inward perception is inaccessible to the senses, because it is not of something away from them, as the world objects are. Though inaccessible to the senses, it is fully palpable to the intelligence, buddhi. When this inmost perception is gained and the delight arising there from is experienced, the mind and intelligence become contented and stable. This possession is an exclusive enrichment, which can never be robbed by anything or anyone. All external possessions are transitory and can be robbed, but this cannot be. Being his own closest within, nay himself, the seeker does not fall from it, nor does he get distanced from it, come what may.

The unswerving state of the mind and intelligence is itself the pinnacle and fulfillment of yoga. This is a point Krishna emphasized in the second chapter itself (verse 53). Seekers often miss this fact and consider yoga to be some special mystic supra-mental state with supernatural powers like levitation etc. Any such abnormality or eccentricity, however strange and mystic it may seem to be, is not at all the gift or blessing of true yoga-sadhana.