Abhidharmakosabhasyam, Volume IV

The Absorptions 1221
[Hsuan-tsang: 3c. There is no rupa in Arupyadhatu.]
This should be proved, say some Schools, for we maintain that
there is some physical matter, rupa, in the Arupyas.
But then why are the arupyas called arupyas, "absences of
physical matter"?
They are called this because their rupa is reduced, in the same
way that a little red {tsatpingala) is called "reddish" (apingala,
"absence of red") (i.17, English trans, p. 75).
So be it; but what type of physical matter is in Arupyadhatu?
i. If you say that this physical matter is neither the body nor the
voice, but merely the physical matter that constitutes bodily and
vocal discipline (kayavaksamvaramatra, the rupa that forms part
of the dharmayatana, iv. p. 561), then how can this discipline exist
in the absence of body and voice? And how can a rupa derived from
the primary elements {bhautika), namely discipline, exist in the
absence of these same primary elements (mahabhutas)? If you
answer that bodily and vocal discipline exists in Arupyadhatu
without the cooperation of primary physical matter, in the same
way that pure discipline exists without primary elements of their
same, i.e., pure, nature, then this answer does not hold, for pure
discipline has impure primary elements for its support, elements
in the sphere in which the Aryan is born (iv.6).
This proof for the absence of physical matter does not hold
only for existence in Arupyadhatu, but also for the absorption of
Arupyadhatu, 22 [in which samvara or discipline, which is rupa, is
also absent].
ii. If you attribute material organs {rupindriya) to the beings in
Arupyadhatu, how can you say that the physical matter of
Arupyadhatu is subtle?
Because their dimensions are very small; the beings are
therefore of reduced rupa (tsadrupa), so the beings are then