Śvetāśvatara Upaniṣad · 3..6
यो रजसि तिष्ठन् यं रजो न वेद यस्य रजः शरीरं यो रजसोऽन्तरो यमयत्येष त आत्मान्तर्याम्यमृतः
yo rajasi tiṣṭhan yaṃ rajo na veda yasya rajaḥ śarīraṃ yo rajaso'ntaro yamayaty eṣa ta ātmāntaryāmy amṛtaḥ
He who, dwelling in passion, whom passion does not know, whose body is passion, who controls passion from within —He is your Ātman, the Inner Ruler, the Immortal.
Now we move from elements to guṇas: rajas (passion/activity) is the principle of movement, desire and change. Passion does not know the one who animates it; it itself is animated. In our yoga practice, this is crucial: when we experience agitation, ambition, intense desire, we can remember that there is something in us that observes this passion without being it. The antaryāmin is not free of rajas —is in it, uses it as instrument— but is not limited by it. I am the one who has passions, not the passions themselves.