We want to have some piece of Chazal that says murex trunculus is the Chilazon for Techeiles – purfura. The Raavya is known about, as was discovered by Bezalel Naor 30 years ago, that Techeiles is purfurin.
People didn’t know what Prifinan meant, and there were those saying that it wasn’t trying to translate the word Karti, let alone Techeiles as Purfirin, rather simply a parallel. This can be kvetched since Brachos gave a number of examples of MiSheyakir, meaning when there’s enough light to make a difference so one knows when to say Shema. One way is when your friend is from 4 Amos, or the difference between a domesticated and wild donkey, and Techeiles/Karti and Techeiles/Lavan. So the claim was that it was to be Purfirin and Prifinan as another thing in the sequence. And Prisinan isn’t a translation of Karti. And there are a lot of creative explanations like from Mendel Singer and others to what the term Prifinan really means, like a robe and hem of a robe, etc. Shlomoh Taitelbaum suggested that perhaps Prifinan was a bad Girsa. Yankelewitz went to a university library to investigate and sure enough it says Prisinin. That was nice and made the Raavya more powerful, but it wasn’t necessarily a bombshell.
The piece that Mordechai Honig מרדכי מ’ הוניג discovered in a privately owned Ashkenazi manuscript puts the Yerushalmi in context. Before, it was unclear why the Yerushalmi was discussing the translation. In fact, we said the reason Chazal never spelled out that Techeiles was purfirin was because they wouldn’t have bothered with a translation. So why is the Yerushalmi even bothering to translate Techeiles?
This translation by the grandson of the Raavya puts it into context. There’s a machlokes Tannaim what Misheyakir is, is Techeiles against Lavan or Karti, which is easier or harder to identify? But also, why this? Why not compare the red of a beard and the red of blood? Anything. What’s special about Techeiles/Karti and Techeiles/Lavan?
The answer is that Chazal had a Kabbala of what time it is and had these Simanim. The Yerushalmi is looking for a background page, some kind of Pasuk to put each one in. Yerushalmi explains the background. Bein Techeiles L’Lavan is because of Ureisem Oso. It being the Techeiles. It means only after daybreak. R’ Eliezer says no, it’s later and the Pasuk means it’s Techeiles as opposed to some other dyed material. Which dyed material? Techeiles and not something dyed similar. Close but not Techeiles is Karti.The Raavya says this is important. There’s a discussion in Meforshai HaMishna is that Karti is a vegetable/leek. The Raavya discusses that there’s a Machlokes Rishonim discussing, does Karti mean leek or is it a leek-colored cloth? The Yerushalmi says that no, it’s a leek-colored cloth, not leek from the grocery store. To make that distinction, the Raavya needs to make that translation to make this clear. Once the first half of the phrase was translated, the second half came along with it and that’s where we have purphirin is Techeiles.
The manuscript gives the background which isn’t explicit in the Raavya. The context tells us that this can only be a translation of Techeiles as this is the whole point of the piece.
Bottom-line: that’s why the text V’Chen Ikkar D’Garsinan is crucial because it links the second part of that Mishna with the first. The later one would make it seem to imply that those are two different Mishnas and one can then get creative as mentioned above.