Karika 17

सङ्घातपरार्थत्वात्त्रिगुणादिविपर्ययादधिष्ठानात्। पुरुषोऽस्ति भोक्तृभावात् कैवल्यार्थं प्रवृत्तेश्च ॥१७॥

saṅghātaparārthatvāttriguṇādiviparyayādadhiṣṭhānāt। puruṣō'sti bhōktr̥bhāvāt kaivalyārthaṁ pravr̥ttēśca ॥17॥

[सङ्घात पर अर्थत्वात् त्रिगुणादि विपर्ययात् अधिष्ठानात्। पुरुषो अस्ति भोक्तृ भावात् कैवल्यार्थं प्रवृत्तेः च॥
saṅghāta = the manifestation happens; para = the other; arthatvāt = for the sake of; triguṇādi = of the three qualities; viparyayāt = by the deformities; adhiṣṭhānāt = supported by; puruṣō = the purusha / being; asti = exists; bhōktr̥ bhāvāt = as an enjoyer; kaivalyārthaṁ = to get liberated; pravr̥ttēḥ = because of its tendencies; ca = and;]

The manifestation happens by the deformities of the three qualities, for the sake of, and supported by, the other. Hence, the Purusha exists as an enjoyer, driven by its tendencies, with the purpose of getting liberated.

The tendencies of the Purusha drives the manifestation. Hence, Purusha is the cause.