dvāvimau puruṣau loke kṣaraścākṣara eva ca |kṣaraḥ sarvāṇi bhūtāni kūṭastho'kṣara ucyate ||
There are two kinds of person (purusha) in this world: the perishable and the imperishable. The perishable is all living beings; the one who stands unchanging is called the imperishable.
Explanation
Krishna begins to explain the highest reality (Purushottama) by first naming two aspects of "person" (puruṣa). The perishable (kṣara) is all beings that change and pass away; the imperishable (akṣara) is what stands unchanged, "like an anvil" (kūṭastha). Commentators differ on the imperishable: some take it as the liberated self or the conscious principle, others as the unchanging source of nature (prakṛti) or as maya's seed.