Tadapiteh samsaravyapadesat IV.2.8 (504)

That (fine body lasts) up to the attainment of Brahman (through knowledge), because (the scriptures) declare the state of relative existence (till then).

Tat: that, aggregate of the elements, the sum total of the subtle elements; Apiteh: till the attainment of Brahman (through knowledge); Samsaravyapadesat: because (scriptures) declare the state of relative existence.

In the text cited in Sutra 1, we have "And fire is merged in the Highest Deity". The meaning is that the fire of the dying man together with the individual soul, the Prana, the aggregate of the organs and the other elements is merged in Brahman.

We now have to consider of what kind that merging is.

The Purvapakshin holds that it is an absolute absorption of things merged, as it is proved that those things have the Highest Deity for their causal mater. For it has been established that the Deity is the causal substance of all things, that have an origin. Therefore that passing into the state of non-separation is an absolute one. This is the final dissolution. Everyone attains the final emancipation at death.

This Sutra says that this merging is not absolute merging. Although Brahman is the causal substance of those elements, they are at the time of death, as in the case of deep sleep and a Pralaya of the world, merged in it only in such a way as to continue to exist in a seminal condition or seed state. Only the functions of these elements are merged and not the elements themselves.

Those subtle elements, fire and so on, which form the abode of hearing and the other organs persist up to final release from the Samsara, which is caused by perfect knowledge, because the scriptures declare that till then the Jiva or the individual soul is subject to relative existence. "Some souls enter the womb for embodied existence as organic beings; others go into inorganic matter, according to their work and according to their knowledge" (Katha Up. II.5.7).

Otherwise the limiting adjuncts of every soul would at the time of death be absorbed and the soul would enter into absolute union with Brahman. Every dying person will reach Brahman. This would render all scriptural injunction and scriptural doctrine equally useless.

Bondage which is due to wrong knowledge, cannot be dissolved but through perfect knowledge (Samyag Jnana). If the merging at death were absolute, then there could be no rebirth.

Sukshmam pramanatascha tathopalabdheh IV.2.9 (505)

(This fine body) is subtle (by nature) and size, because it is so observed.

Sukshmam: subtle; Pramanatah: as regards size; Cha: and; Tatha: thus, so; Upalabdheh: because it is experienced, it being observed.

The elementary matter of fire and the other elements which form the substratum of the soul, when passing out of this body, must be subtle in its nature and extent. This follows from the scriptural passages, which declare that it passes out by the Nadis and so on.

Its thinness renders it capable of passing out through the thin and subtle Nadi and its transparency is the cause of its not being stopped or obstructed by any gross substance, and not being seen by the by-standers when it passes out at death.

Nopamardenatah IV.2.10 (506)

Therefore, (this subtle body is) not (destroyed) by the destruction (of the gross body).

Na: not; Upamardena: by the destruction; Atah: therefore, because of this reason.

On account of this great subtlety the subtle body is not destroyed by what destroys the gross body, viz., burning and the like.

Asyaiva chopapatteresha ushma IV.2.11 (507)

And to this (subtle body) alone does this (bodily) heat belong, because this (only) is possible.

Asya: of the subtle body; Eva: verily, certainly, alone; Cha: and, also; Upapatteh: it being possible, because of possibility; Esha: this; Ushma: (bodily) heat.

To that same subtle body belongs the warmth which we perceive in the living body, by means of touch. That bodily heat is not felt in the body after death, while such qualities as form, colour and so on, continue to be perceived. The bodily heat is felt as long as there is life. It follows from this that the heat resides in something different from the body, as ordinarily known. The subtle body imparts its own heat to the gross body and keeps it warm as long as it remains alive. Scripture also says, "He is warm if going to live; cold if going to die."