There is a helpful resource on kāya here -
Some findings -
- While DN 9 uses attapaṭilābha, its parallel DA28 consistently uses 身 (body). This reading corroborates the idiomatic usage of kāya in other Pali suttas as being either -
(a) rūpī cātumahābhūtiko; or
(b) of the manomaya variety being merely rūpin.
Thankfully, DA28 preserves for us the formless kāya s (eg 有想無想處天身 at the end of the standard listing of 4 formless attainments) corresponding to DN 9’s arūpa attapaṭilābha.
- Even within the Pali texts, traces of the older (and probably pre-Buddhist) idiom of the kāya as a form of Being can be found in the DN 1 passages on the Annihilationists’ proposition regarding kāyassa bhedā of someone who’s being born into the Formless Attainments, eg -
Tamañño evamāha: ‘atthi kho, bho, eso attā, yaṃ tvaṃ vadesi, neso natthīti vadāmi; no ca kho, bho, ayaṃ attā ettāvatā sammā samucchinno hoti. Atthi kho, bho, añño attā sabbaso ākiñcaññāyatanaṃ samatikkamma “santametaṃ paṇītametan”ti nevasaññānāsaññāyatanūpago. Taṃ tvaṃ na jānāsi na passasi. Tamahaṃ jānāmi passāmi. So kho, bho, attā yato kāyassa bhedā ucchijjati vinassati, na hoti paraṃ maraṇā, ettāvatā kho, bho, ayaṃ attā sammā samucchinno hotī’ti. Ittheke sato sattassa ucchedaṃ vināsaṃ vibhavaṃ paññapenti.
- Which leads to SN 12.2 which uses khandhānaṃ bheda
in lieu of kāyassa bheda.