द्वाविमौ पुरुषौ लोके क्षरश्चाक्षर एव च | क्षरः सर्वाणि भूतानि कूटस्थोऽक्षर उच्यते ||
dvāv imau puruṣau loke kṣaraś cākṣara eva ca kṣaraḥ sarvāṇi bhūtāni kūṭa-stho 'kṣara ucyate
Translation
There are two Purushas in this world: the perishable (Kshara) and the imperishable (Akshara). All beings are the perishable; the unchanging is called the imperishable.
Interpretation
Krishna now introduces the threefold division that gives this chapter its name (Purushottama Yoga). The first two: Kshara Purusha — all perishable beings, the entire manifest universe in its constant flux of creation and destruction; and Akshara Purusha — the unchanging, the immovable, the Kutastha (the 'summit-stander'), which is the unmanifest ground of existence, Prakriti in its undifferentiated state, or the totality of souls as an unmoving principle. These two — perishable manifestation and imperishable ground — represent the scope of conventional metaphysics.