I. I’ve searched the forum and haven’t found any explanation for this phrase yet, so it would be good if there is a detail explanation on this matter.
While reading the sutta, when encountering this sentence, I thought that this might be the key for the breakthrough:
“Susīma, first comes knowledge of the stability of natural principles. Afterwards there is knowledge of extinguishment.”
II. And furthermore, I wonder what is the relationship between the “knowledge of the stability of natural principles” and this practice of clear-seeing that the Buddha has taught Susima:
“So, Susīma, you should truly see any kind of form/feeling/perception/choices/consciousness at all—past, future, or present; internal or external; coarse or fine; inferior or superior; far or near: all form/feeling/perception/choices/consciousness—with right understanding: ‘This is not mine, I am not this, this is not my self.’"
III. I have practiced according to the above instruction for quite some times now, and through repeated reflection upon 5 subjects (5 clinging-aggregates) and their 11 attributes (past, future, …), I’m slowly understand somewhat about the Buddha’s teaching. But still not as clear as daylight, so I hope that I will receive details instruction on doing this kind of reflection too.
Ironically, I think you’re making the same mistake Susima did: jumping to the end.
I take the passage you highlighted not as the instruction so much as a statement of the result. The practice that the Buddha recommended Susima came before this punchline: See the three characteristics in everything you experience.
The point isn’t to diversify our perception but to unify it.
Essentially this is referring to the fact that the “principles” of Dhamma, such as impermanence, dependent origination, or the four noble truths, are laws of nature and do not change.
That doesn’t mean that they are permanent, of course, because they are not “things”. They are, rather, “descriptions inferred from experience” (upādāya paññatti). Right now we can describe our experience as impermanent. A minute ago we could describe it as impermanent. A year ago, or indeed, at the start of the Universe, we could describe it as impermanent, and we would be correct. In the future, too, these principles remain the same.
It is because these “principles” always accurately describe nature that they have a liberative power. We are not just being freed from whatever this is right now, but from all things in the past and future. Even though we don’t experience them directly, we infer their nature by understanding the “stability of natural principles”.