पुरुषः प्रकृतिस्थो हि भुङ्क्ते प्रकृतिजान्गुणान्।कारणं गुणसङ्गोऽस्य सदसद्योनिजन्मसु ॥

The soul residing in Nature and identifying itself with the body and the senses which are modifications of Nature acts through the alities of Nature and experiences pleasure and pain and delusion. It thinks, I am happy, I am miserable, I am deluded, I am wise. When it thus identifies itself with the alities, it assumes individuality and takes birth in pure and impure wombs.The soul (Jivatma) enjoys the sensual objects in conjunction with the body, mind and the senses and thus becomes the enjoyer. Brahman is the silent witness and nonenjoyer. The souls attachment to the alities of pleasure, pain and delusion is the chief cause of its birth. If you add the word Samsara to the second half of the verse, it will mean Attachment to the alities is the cause of Samsara through births in good and evil wombs.Good wombs (Sat Yoni) are those of the gods and the like evil wombs (Asat Yoni) are those of lower animals. The human womb is partly good and partly evil on account of mixed Karmas.Purushah prakritisthah Purusha (the soul) seated in Prakriti (Nature). This is Avidya (ignorance). Attachment to the alities of Nature is Kama (desire). Avidya and Kama are the cause of Samsara.Jnana (wisdom) and Vairagya (dispassion) will destroy ignorance and desire. (Cf.XIV.5XV.7)