Reply To: Techeiles 🔵❎🐌☑️🐟

Chacham: You have said (and I said it also) that it’s clear from the gemara (eruvin 96b and menachos 43a) that the only blue dyes that chazal knew of were techeiles and kala ilan. Now this is only a raya if you assume that kala ilan specifically refers to plant indigo and nothing else (an assumption which you do in fact state based on rishonim who translate it as such. V’ayin levush ha’aron who proves this from the fact that the gemara in BK uses kala ilan in a sugya unrelated to techeiles). My problem is that I’m not so sure that this is an undisputable claim. The Kesef Mishna (hilchos tzitzis 2:8) says: ??? ????? ?? ????? ???? ??? ?? ?????, ?????? ?? ???? ??? ??? ???? ???? ???? ??? ???? ???? ????? ??? ??? ?????? which would seem to indicate that kala ilan refers to any imitation of techeiles. Thus, it could be that Murex Trunculus is (included in) kala ilan which would explain why there’s no specific warning in the gemara against using murex trunculus. (By the way I’m saying this all in a vacuum of all other rayos.) Do you know of any answer to this? Theoretically you could say that it can’t be because murex trunculus passed the chemical test, but perhaps one could argue that we’re not doing the gemara’s test properly.