And it was in source about Trinimac no less.... I knew it was somewhere which I read dozens of times but instead we were looking at the wrong place. Good find, Goldie.

I only found that source because I'd googled "Dunmer bone, finger, string and tongue is buried in each corner of the house" and it took me to Provisional House Studies written by a Phil T

He ain't gettin' on no plane, Fool. ;)

Right, there is another... I swear by Dibella's G- that I read Talos knew about Paarthurnax and forbade his Blades from attacking. It has been many years since I (think) I read that one and so it could be a futile search. If you can find any such referrence then you are the sniffer doggy of lore :)

That sounds like some oog, mate. But I have no doubt that Golden Fool the Lore Hound will give it a shot :D

Not the exact source but they talk about it here: Would Talos Stormcrown have met Paarthurnax ? : teslore

So far I have found this discussion on Reddit (edit: it;s the same one Veloth links to) in which someone is asking whether Talos met Paarthanax based on a quote from Paarthy in which he claims the Last Dragonborn is the first non-greybeard to talk to him in over a hundred years. In which a couple of people claim he knew and forbade the blades from doing anything or at the very least didn't tell them about him, but they don't provide any sources.

And this line from UESP's lore page on Talos:

Before he left, he learned the secrets of the high peak winds -- the roar of the winter blast, and the warm silk of the summer updrafts.

Depending on how you look at the first part you could infer that Talos; or Hjalti, went to the Throat and learnt from Paarthy.

 

The "source" I am after is presented a if it's in-universe. So if it's an OOG then it's monkey-truth I adopted years ago. It's like written in Pocket Guide style, a sentence that would fit into one of those perfectly. That said, in that link the Legate's sentence stands out:

Delphine stated that Paarthurnax was protected by the Greybeards, and later the Septims. This implies they had awareness of him and explicitly forbade the Blades from engaging him.

Because I have a love of Delphine, it could be that I extrapolated and used her dialogue to make an assertion in a past pro-Delphine rant. Then read my words and adopted them as my own :p

Phil, when I saw that post last night I actually went and checked Delphine's dialogue from the Paarthurnax quest on UESP, and she only states that the Greybeards have been protecting. There was no mention of the septims. Now they may have gotten the line wrong, I'm not sure since I haven't played the quest in years.

It could be a case of extrapolative reasoning. I asked the librarians in TIL last spring the very same question and the answer seems to be the same - it is something which comes up in the lore community often but doesn't have a direct source, rather a case of reasonable deduction that Tiber knew of Paarthurnax being mantled by the collective unconcious. The missing link as to how we as a community came to the conclusion he forbade any Blade interference is a puzzle, though.

Someone in that discussion that Veloth and I linked to, claims the blades didn't actually know about him. But if that was the case how did they find out about him in Skyrim? When I was searching I started to think about the process of learning the way of the voice and remembered that eventually every student would meet Paarthy eventually. So it's safe to assume one of the aspects of Talos met him when they visited them.