Bhagavad-Gita: Chapter 11, Verse 18

Rudra Vaisnava Sampradaya:

Visnuswami

Sridhara Swami's Commentary

Since the Supreme Lord Krishna's almighty power is beyond the material conception it is correctly stated in Vedic scriptures that He the Ultimate destination and what is to be known for seekers of moksa or liberation from material existence. He alone is imperishable, the Supreme salvation for all living entities, the Supreme refuge without a second for all creation. Therefore Lord Krishna is eternal, immutable, the preserver, the protector and the sustainer of sanatan dharma or the eternal spiritual principles of righteousness for all times and He is absolutely without a doubt the original Supreme Lord of all lords and created beings.

Brahma Vaisnava Sampradaya:

Madhvacarya
There is no commentary for this verse.

Sri Vaisnava Sampradaya:

Ramanuja

Ramanuja's Commentary

The Vedic scriptures known as the Upanisads declare also that Lord Krishna is aksaram paramam the Supreme immutable ultimate reality and declared in the Vedic scriptures as that which is essential to be known. The word veditavyam means He is only to be know by the absolute authority of the Vedas. The word avyayah means that which is imperishable and can never be diminished for in whatever aspect or form or manifestation Lord Krishna wills to be that will eternally be existing. The phrase sasvata-dharma- gopta means the Supreme Lord Krishna is the eternal preserver of eternal righteousness embodied in the Vedic scriptures. This is done by Himself and by His authorised avatars o incarnations and expansions as revealed in Vedic scriptures such as Narayana, Rama, Vishnu, Narasimhadeva, Buddha etc. The words sanatanas tvam puruso means Lord Krishna is the eternal spirit and primal consciousness of all creation as affirmed in the Taittriya Upanisad III.XII beginning vedaham etam purusam meaning I perceive the magnificent Purusa. Also in the Mundaka Upanisad I.I.IV beginning dve vidye veditavye meaning: The Purusa is more sublime than the most sublime. All this is as the ornament of the complete cosmic creation Lord Krishna exhibited His visvarupa or divine universal form and is understood as such.

Kumara Vaisnava Sampradaya:

Nimbaditya

Kesava Kasmiri's Commentary

The Supreme Lord Krishna's magnificent is beyond the ability of the mind and senses to fathom and comprehend. It is declared in the Brhadaranyaka Upanisads III:VIII:X: O Gargi if one performs ceremonial rituals, worship and propitiation and undergoes rigid austerities for thousands of lifetimes without knowledge of Lord Krishna being the Supreme God of all gods; then the results of all such activities is limited and minimal indeed. Verily one who having lived their span of life in the material existence who departs this world ignorant and oblivious to the reality that the Supreme Lord Krishna is the ultimate cause of their very existence as well as the source of the complete cosmic creation is considered to be pitiful and their condition is lamentable. But one who departs this world at the end of their life knowing the absolute paramount position of the Supreme Lord Krishna is exalted. The Supreme Lord Krishna the origin and source of all things animate and inanimate is most worthy to be known to those who value their own best interests. He is eternal, immutable, the spiritual substratum pervading all existence, the support, the preserver and the refuge for all creation. There is no change or diminution in His form, qualities, attributes and potencies. Lord Krishna and His avatars or incarnations and expansions authorised in Vedic scriptures are the eternal protector of the Vedas and the principles of righteousness delineated very precisely and concisely in the Vedic scriptures as they all are verily righteousness personified. The Primal Supreme Being the ancient of all.