18.51-53
One becomes fit to attain Brahman when he or she possesses a purified intellect and firmly restrains the senses, abandoning sound and other objects of the senses, casting aside attraction and aversion. Such a person relishes solitude, eats lightly, controls body, mind, and speech, is ever engaged in meditation, and practices dispassion. Free from egotism, violence, arrogance, desire, possessiveness of property, and selfishness, such a person, situated in tranquility, is fit for union with Brahman (i.e., realization of the Absolute Truth as Brahman).