Reference for Bekhorot 33:45

מודה ר"מ בשעיר של ראש חדש דבעינן בן שעירה מאי טעמא

Said R'Aha B'Jacob: All [the authorities concerned, even R'Meir] agree that by using its wool one does not become liable to lashes for kil'ayim.<span class="x" onmousemove="('comment',' The wearing of a garment containing a mixture of wool and linen.');">²⁵</span>

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