B.G 15.16, 17 and 18
dvāv imau puruṣau loke kṣaraś cākṣara eva ca। kṣaraḥ sarvāṇi bhūtāni kūṭastho'kṣara ucyate ॥16॥
In this world, there are two types of beings: Kṣara i.e. the changing and Akṣaraḥ i.e. the unchanging. All creatures are Kṣaras i.e. the changing, but the imperishable insentient, i.e. Prakrti, is called the Akṣaraḥ i.e. the unchanging.
uttamaḥ puruṣastvanyaḥ paramātmetyudāhṛtaḥ। yo lokatrayamāviśya bibhartyavyaya īśvaraḥ ॥17॥
The highest person is said to be another, the Supreme Ātman, who, entering the three worlds, sustains, the Lord of the imperishable Paakrti.
yasmāt kṣaramatīto'hamakṣarādapi cottamaḥ। ato'smi loke vede ca prathitaḥ puruṣottamaḥ ॥18॥
I am known as the Supreme Person in the world and the Vedas because I transcend both the 'Kshara', subjected to change, and the 'Akshara', the unchanging.
Gīta Bhāshya 15.16, 17 and 18
The word 'Kṣara' is used to refer to beings starting from Lord Brahma. The words 'Kūṭastha' and 'Akshara' refer to Prakrti.
kṣarabhūtāni brahmādīni। kūṭasthaḥ prakṛtiḥ। tathāca śārkarākṣyaśrutiḥ-
The word 'Kṣara' is used to refer to beings starting from Lord Brahma. The word 'Kūṭastha' refers to Prakrti. This is also stated in the Śārkarākṣya Vedic text:
"prajāpatipramukhāḥ sarvajīvāḥ kṣarokṣaraḥ puruṣo vai pradhānam। taduttamaṃ cānyamudāharanti jālajālaṃ mātariśvānamekam॥"
"All the beings starting from the lord of all creatures, Prajāpati, are termed 'Kshara', i.e. subjected to change. The 'Akshara', i.e. unchanging, is that 'Pradhana', i.e. Prakrti. Superior to both, that supreme person is different, termed as the net of nets, the singular Mātariśvan."
iti ॥16॥
- stated thus.
॥ iti śrīmadānandatīrthabhagavatpādācāryaviracite śrībhagavadgītābhāṣye pañcadaśādhyāyaḥ ॥
Thus ends the fifteenth chapter of the Śrī Bhagavad Gītā commentary composed by the revered teacher Ānandatīrtha Bhagavatpāda.