A paticca-samuppada-like progression leading to vision of a method to bring about Nibbāna.
Read the Sutta
A little six-liner, about which I have written the following in a footnote:
The sutta uses the 'causitive' form. But I object on general principles to the whole idea of causation.
Instability does not cause pain perception.
One perceives instability; using that perception of instability one, of one's self, (not 'because of', but 'one is enabled by that to'), perceives pain or maybe not.
If instability caused pain-perception everyone would perceive pain; if pain caused not-self-perception everyone would perceive not-self.
If eveyone perceived not self everyone would let go of living, become dispassionate, and bring Pain to an end, snap fingers everyone's an Arahant.
Both Hare's and Bhk. Bodhi's translations suggest the meaning:
"the perception that pain is inherent in that which is unstable';
'the perception that not-self is inherent in that which is painful'.
These are both statements that are consistent with Dhamma, but neither of them are what is being said here in this sutta.
Hare's 'the idea of 'ill' in impermanence' misleads in that the letter directs one to an intellectual understanding, not a direct perception.
This is consistent with his translation of 'vijja' as 'wisdom' and 'saññā' as 'thought', but does not much help one attain the "perceptions" necessary to "see" a method for attaining freedom and does not accurately give the letter which should reflect the idea that the one perception is based on the other.
Bhk. Bodhi's 'perception of suffering in the impermanent' at least points to the direct perception but it too ignores the letter.
The idea of the sutta is a mini-version of the paticca-samuppada: the vision of a method for attaining utter detachment provided by the sequence of perceptions. A progression which insists on there being a relationship of dependence between the six items.
that leads to this,
this leads to that
and this and this and this.
It is not 'the constituents of vision are: the perception of instability, and the perception of pain in instability, and the perception of not-self in instability, and the perception of letting go, and the perception of dispassion and the idea of ending;'
'the constituents of vision are the perception that the perception of instability leads to the perception of pain which leads to the perception of not-self, the perception of letting go, the perception of dispassion, and the perception of ending.'
It's being scatter-brained versus being focused.
The one way leaves one saying "OK", the other way leaves one saying "I see!"
One of the original names for the Buddhsits was 'vibanghers', 'hair-splitters'; we need to respect that level of precision in our translations. I include me in this caution.