SN 40.9 a-nimitta samadhi, difference between perceptions (sañña) and viññana/consciousness

I noticed something interesting about a-nimitta samadhi, which sheds some light on the difference between perceptions (sañña) and viññana/consciousness. In the first suttas of SN 40, Moggallana is working on mastering the 8 samadhi attainments, and the impure verison of each attainment, the words used are paying attention (manasi karoti) to the perceptions (sañña) of the impurity of that attainment. For animitta samadhi however, instead of perception, he uses consciousness (viññana).


From SN 40.9:

STED a-nimitta ceto-samādhi

‘idha bhikkhu	'Here (a) monk,
sabba-nimittānaṃ a-manasi-kārā	(regarding) all-signs, no-attention-(is)-given (to them).
a-nimittaṃ ceto-samādhiṃ upasampajja viharati.	Sign-less concentration-of-mind (he) enters (and) dwells.
ayaṃ vuccati a-nimitto ceto-samādhī’ti.	This (is) called Sign-less concentration-of-mind.'"

impure version of animitta

so khvāhaṃ, āvuso,	"** Then-****, friends,
sabba-nimittānaṃ a-manasi-kārā	(regarding) all-signs (having) non-attention-given (to them),
a-nimittaṃ ceto-samādhiṃ upasampajja viharāmi.	(the) sign-less concentration-of-mind (I) entered (and) dwelled (in).
tassa mayhaṃ, āvuso,	While I, *****,
iminā vihārena viharato	***** dwelt (in that) dwelling,
nimitt-ānusāri viññāṇaṃ hoti.	signs-(were)-followed (by my) consciousness ****.