Karika 16

कारणमस्त्यव्यक्तं प्रवर्तते त्रिगुणतः समुदयाच्च। परिणामतः सलिलवत् प्रतिप्रतिगुणाश्रयविशेषात् ॥१६॥

kāraṇamastyavyaktaṁ pravartatē triguṇataḥ samudayācca। pariṇāmataḥ salilavat pratipratiguṇāśrayaviśēṣāt ॥16॥

[कारणम् अस्ति अव्यक्तं प्रवर्तते त्रिगुणतः समुदयात् च। परिणामतः सलिलवत् प्रति प्रति गुण आश्रय विशेषात्॥
kāraṇam = the cause; asti = exists; avyaktaṁ = in the un-manifest; pravartatē = instigates; triguṇataḥ = through three qualities; samudayāt = by their combination; ca = and; pariṇāmataḥ = from its effects; salilavat = flows with ease; prati prati = different different / varied multiple; guṇa āśraya = sheltered in the qualities; viśēṣāt = especially;]

The cause exists in the un-manifest, that instigates the combination of three qualities. Varied multiple effects flow with ease, specially sheltered in the qualities.

It is critical to note, unambiguously cause is attributed to the unmanifest 'Purusha' or the individual soul.