kṣetra-kṣetrajñavibhāgayoga - Verse śloka 21
śloka 21
kāryakāraṇakartṛtve hetuḥ prakṛtirucyate |
puruṣaḥ sukhaduḥkhānāṃ bhoktṛtve heturucyate ||13-21||
Translation
Prakriti is said to be the cause in the production of effect and cause, and Purusha is said to be the cause in the experience of pleasure and pain.