How can we conclude that something is unarisen and eternal?
Imagine, for example, that you're trying to travel to Paris (or to Rome, or Varanasi, or anywhere else).

So, you ask people, "How to get to Paris?" -- and you follow road signs, which say, "This way to Paris."

When you get to Paris, after you arrive, I don't think you ask yourself, "How do I know this is Paris?"

I think that descriptions of nirvana (like "unarisen") should be understood as instructions or directions like this.



I don't know, maybe another analogy is like, you go with someone to the sea-shore, and they say, "That ocean is always there." You look, and what you see are waves which appear and disappear, and so it's difficult to see what's constant, to see that there is anything that's constantly there.