Bhagavad Gita 15.16

द्वैविमौ पुरुषौ लोके क्षरश्चाक्षर एव च ​​|
क्षर: सर्वाणि भूतानि कूटस्थोऽक्षर उच्यते

Translation

There are two kinds of beings in creation, the kṣhar (perishable) and the akṣhar (imperishable). The perishable are all beings in the material realm. The imperishable are the liberated beings.