Bhagavad-Gita: Chapter 8, Verse 6

Rudra Vaisnava Sampradaya:

Visnuswami

Sridhara Swami's Commentary

It is not that this rule is only applicable regarding remembering the Supreme Lord Krishna and attaining His nature. What then is it applicable too, one may wonder? This rule applies to whatever object or being one might envision as the last thought before leaving the physical body at the moment of death. Without fail one will become the very thing which one was envisioning when they died. The cause of smaran or remembering something specific at the time of death is due to constantly thinking about or meditating upon something with the mind fully absorbed in it.

Brahma Vaisnava Sampradaya:

Madhvacarya

Madhvacarya's Commentary

Lord Krishna states smaran bhavam tyajaty ante kalevaram meaning leaves the body at the final moment remembering. To insure that there is no confusion or contradiction in the minds of the ignorant, the adjective ante meaning at the final moment is spoken. It is not that the Supreme Lord should be meditated on only at the moment of death. To the contrary He should be remembered, recollected and contemplated upon at every moment. The spiritually developed have no such confusion as their remembrance of the Supreme Lord is the focal point of their lives and constant. To think that such remembrance is to be utilized only as a one time proposition at the moment of death is an unwise consideration.

The Skanda Purana states that: There is no doubt that at the time of death it is not easy to remember the Supreme Lord due to the difficulties of dying. At the time of departure from the body one must be attuned to the inner nature. The word bhava means internal consciousness. The internal consciousness is that which abides internally thus it is said it is the nature which abides within. Only if one contemplates something continuously does it become fixed as internal consciousness and manifest as a part of one's nature. Otherwise what one will think at the moment of death will be mere ego related ideas derived from one's own mundane empirical experiences.

Sri Vaisnava Sampradaya:

Ramanuja

Ramanuja's Commentary

Whatever image prominently floats in one's thoughts at the moment of death and one leaves one's physical body with that final thought one will become in their very next life. This is what Lord Krishna is stating in this verse. Their final thought will become form. One's final thought will naturally be what was constantly reflected upon and mediated on during their span of life based upon one's association and daily habits.

Kumara Vaisnava Sampradaya:

Nimbaditya

Kesava Kasmiri's Commentary

Not only by thinking of Lord Krishna alone does one attain His eternal nature; but whatever one thinks at the moment of death one becomes without fail. This is being stated with the words yam yam meaning whatever. Whatever one is thinking at the last moment of death will transport one to become the very object or conception one contemplated while dying. The reason Lord Krishna also gives with the words sada tad-bhava-bhavitah meaning due to being completely absorbed in such contemplation the powerful prominence of the final thought and image infuses itself upon the consciousness determining their next birth.