Upvote:0
I think It's because it is the most appropriate way of classifying everything by grouping of five.
Grouping by a singlefold classification would be "all" as is defined in sabba sutta. It is from that a matter of inference.
In that you infer elements that are not included in the previously inferred one's until it is no longer possible to name an element that isn't included in the five fold classification.
The Sabba Sutta also gives a twelvefold classification.
"Monks, I will teach you the All. Listen & pay close attention. I will speak."
"As you say, lord," the monks responded.
The Blessed One said, "What is the All? Simply the eye & forms, ear & sounds, nose & aromas, tongue & flavors, body & tactile sensations, intellect & ideas. This, monks, is called the All. [1] Anyone who would say, 'Repudiating this All, I will describe another,' if questioned on what exactly might be the grounds for his statement, would be unable to explain, and furthermore, would be put to grief. Why? Because it lies beyond range."https://www.accesstoinsight.org/tipitaka/sn/sn35/sn35.023.than.html
Here one can't name an inferrable element #13 that is rightly inferred and isn't included.
It is the same principle but the grouping is by five for khanda.
The 5fold classification is needed to delineate rupa, arupa and the genesis of those. The five are otherwise rupa & any other of the two because the 4 are conjoined but need delineation to explain genesis and factors of the rupa and the arupa states.
Upvote:1
Well some scholars say that the hindus (and jains?) already talked about the various skandhas.
Ex a famous article "Playing with Fire: The pratītyasamutpāda from the perspective of Vedic thought, by. Joanna Jurewicz. Journal of the Pali Text Society 26 (2000)" https://pdfs.semanticscholar.org/ba71/8e6966ab946ebb5138a06b13ed6762a809fe.pdf
and the famous book Nama-Rupa and Dharma-Rupa: Origins and Aspects of an Ancient Indian Conception https://books.google.com/books?id=w9M-z-JVSa0C
But the Vedists do not understand them. For instance the hindus do not understand that the contact is the condition for the arising of appealing-unappealing like in the dependant origination in the suttanipata https://www.accesstoinsight.org/tipitaka/kn/snp/snp.4.11.than.html . In buddhism, it is only through this direct knowledge that disillusion occurs and letting go happens which is full enlightenment https://suttacentral.net/sa60/en/analayo
If there were no gratification in the ear … nose … tongue … body … mind, sentient beings wouldn’t love it. But because there is gratification in the mind, sentient beings do love it. If the mind had no drawback, sentient beings wouldn’t grow disillusioned with it. But because the mind has a drawback, sentient beings do grow disillusioned with it. If there were no escape from the mind, sentient beings wouldn’t escape from it. But because there is an escape from the mind, sentient beings do escape from it.
https://suttacentral.net/sn35.17/en/sujato
The skhandas are the way they are because they are ''the all'' and what has to be abondoned as in https://www.accesstoinsight.org/tipitaka/sn/sn35/sn35.023.than.html and https://www.accesstoinsight.org/tipitaka/sn/sn35/sn35.024.than.html