Yechiel Michel Epstein

“ And the Rif and the Rambam ruled that the obligation with regards to other [types of] clothing is rabbinic. And Rashi and Tosafot and the Rosh and the Semag ruled that they are obligated based on Scripture, and this is how Rema ruled in Se'if 1. ”

“ Artzos HaChaim, he brought a proof to this from a mishna in the beginning of the 9th chapter of Kilayim, ???? wool and linen, and not ??? tzitzit. And perhaps it is because ??? is also rabbinic - that there is no obligation. ”