I would like to specifically know what the definitions of attiphath yishma'elim were among the Geonim. The opinions of the Rishonim on the subject seem to be convoluted (i.e. no one really knew what ...
The Mishna in M’nachot 4:1 says that the mitzvah of the white tzizit is not gone if there is no techelet, and the mitzvah of the techelet is not gone if there is no white. That seems a straight ...