By knowledge the understanding can be purged off of its impurities The understanding may be engaged for purifying the mind. The senses should be restrained by the mind. Performing all this, one may attain to the Unchangeable.
ज्ञानेन निर्मलीकृत्य बुद्धिं बुद्ध्या मनस्तथा। मनसा चेन्द्रियग्राममक्षरं प्रतिपद्यते॥