Know that both nature and spirit are without beginning, and know also that modifications and qualities arise from nature.

Both prakṛti and puruṣa are anādi — beginningless. This is standard Sāṅkhya doctrine. The two principles are co-eternal.

The vikāras (evolutes) and guṇas originate from prakṛti alone. Spirit is not modified; it merely witnesses the modifications of nature.

Understanding this distinction between the unchanging witness and the ever-changing field is the essence of discriminative wisdom (viveka-khyāti).