Mbh 12.301.6b

Like unto a path of this nature, few Brahmanas can tread alone the Yoga-path with ease and comfort. That man who, having betaken himself to this path, ceases to go forward (but turns back after having made some progress), is regarded as guilty of many faults. Men of cleansed souls, O lord of Earth, can stay with ease upon Yoga-contemplation which is like the sharp edge of a razor. Persons of uncleansed souls, however, cannot stay on it. When Yoga-contemplation becomes disturbed or otherwise obstructed, it can never lead the Yogin to an auspicious end even as a vessel that is without a captain cannot take the passengers to the other shore. That man, O son of Kunti, who practises Yoga-contemplation according to due rites, succeeds in casting off both birth and death, and happiness and sorrow. All this that I have told thee has been stated in the diverse treatises bearing upon Yoga. The highest fruits of Yoga are seen in persons of the regenerate order. That highest fruit is identification with Brahma. The high-souled Yogin, possessed of greatness, can enter into and come out of, at his will, Brahma himself who is the lord of all deities, and the boon-giving Vishnu, and Bhava, and Dharma, and the six-faced Kartikeya, and the (spiritual) sons of Brahmana, the quality of Darkness that is productive of much pain, and that of Passion, and that of Sattwa which is pure, and Prakriti which is the highest, and the goddess Siddhi who is the spouse of Varuna, and all kinds of energy, and all enduring patience, and the bright lord of stars in the firmament with the stars twinkling all around, and the Viswas, and the (great) snakes, and the Pitris, and all the mountains and hills, and the great and terrible oceans, and all the rivers, and the rain-charged clouds, and serpents, and trees, and Yakshas, and the cardinal and subsidiary points of the compass, and the Gandharvas, and all male persons and all female ones also.