The entire content of this mail is from Shri V N Gopala Desikan's Srimad Bhagavad Gita, published by Vishishtadvaita Research Centre, Chennai and The Bhagavad Gita by Swami Chidbhavananda published by Ramakrishna Mission
The Facets of Brahman 16-20
1 Gita Sloka Every Day - Chapter 15 - Purushottama Yoga - Sloka 16
Dvau imau purushau loke ksharah cha aksharah eva cha I
Ksharah sarvani bhutani kutasthah aksharah uchyate II sloka 16
द्वौ इमौ पुरुषौ लोके क्षरः च अक्षरः एव च I
क्षरः सर्वाणि भूतानि कूटस्थः अक्षरः उच्यते II श्लोक 16
There are two kinds of purushas mentioned in the vedas, known as kshara (destructible) and akshara (indestructible). The perishable is all beings and the imperishable is the Kutastha or the unchanging.
The kshara denotes the class of souls, who because of their past karma, are associated with bodies (which are the modifications of the non-intelligent prakriti), starting from Brahma, down to the grass etc. This kind of souls (kshara) are also called as baddha (ie. bound by samsara)
The second kind of souls is called as akshara or indestructible. These souls are released from bondage of samsara, due to the destruction of their past karmas. Theri association with the bodies of devas, men etc. has come to an end. Theya re the liberated souls and are called as muktas.