As one can understand the presence of the air by the aromas it carries, so, under the guidance of the Supreme Personality of Godhead, one can understand the living soul by these three divisions of intelligence. These three divisions, however, are not the soul; they are constituted of the three modes and are born of activities.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
एभिस्त्रिवर्णैः पर्यस्तैर्बुद्धिभेदैः क्रियोद्भवैः । स्वरूपमात्मनो बुध्येद्गन्धैर्वायुमिवान्वयात्
ebhistrivarṇaiḥ paryastairbuddhibhedaiḥ kriyodbhavaiḥ | svarūpamātmano budhyedgandhairvāyumivānvayāt
SB 7.7.26