A man develops a subtle power as a result of the strict observance of celibacy for twelve years. Then he can understand and grasp very subtle things which otherwise elude his intellect. Through that understanding the aspirant can have direct vision of God. That pure understanding alone enables him to realize Truth.
RamakrishnaThe rishis of old attained the Knowledge of Brahman. One cannot have this so long as there is the slightest trace of worldliness. How hard the rishis laboured ! Early in the morning they would go away from the hermitage, and would spend the whole day in solitude, meditating on Brahman. At night they would return to the hermitage and eat a little fruit or roots. They kept their mind aloof from the objects of sight, hearing, touch, and other things of a worldly nature. Only thus did they realize Brahman as their own inner conciousness.
Ramakrishna