B.G 8.21
avyakto'kṣara ityuktastamāhuḥ paramāṁ gatim। yaṁ prāpya na nivartante taddhāma paramaṁ mama ॥21॥
The unmanifest is called the imperishable; that is said to be the supreme goal. Having attained it, they does not return; that is My ultimate abode, the essential natural form.
Gīta Bhāshya 8.21
The phrase 'Having attained which, they do not return' refers to the context from previous verses. 'avyaktaṁ' - the Supreme lord Viṣṇu. 'Dhāma' - essential true natural form.
avyakto bhagavān। 'yaṁ prāpya na nivartante' - iti 'māmupetya' ityuktasya parāmarśāt।
The unmanifest reffered here is the Supreme Lord. The phrase 'Having attained which, they do not return' refers to the earlier statement 'Having reached Me' as an implicit reference.
"avyaktaṁ paramaṁ viṣṇum"
"The unmanifest is the Supreme lord Viṣṇu."
- iti prayogācca gāruḍe।
- used as such in the Garuḍa Purana.
dhāma svarūpam।
The word 'Dhāma' refers to the essential true natural form.
"tejaḥ svarūpaṁ ca gr̥haṁ prājñairdhāmeti gīyate।"
"The wise declare that radiance, essential true natural form, and abode are called 'Dhāma'."
ityabhidhānāt ॥21॥
- such is the declaration (in the ancient Sanskrit dictionary).