Kilayim in bigdei kehunah
The Rambam says in Hilchos Kilayim (10:32): כהנים שלבשו בגדי כהונה שלא בשעת עבודה אפילו במקדש לוקין מפני האבנט שהוא כלאים ולא הותרו בו אלא בשעת עבודה שהיא מצות עשה כציצית “If cohanim wear bigdei kehunah while they are not performing the avodah even if they are not in the beis hamikdash then they receive malkos because the avnet contains kilayim and it was only permitted for the cohanim to wear this garment while performing the avodah .” The Ravad argues with the Rambam and says: טעה בזה שהרי אמרו (ביומא בפרק בא לו) כהן גדול במקדש אפילו שלא בשעת עבודה מותר כו' “The Rambam has made a mistake in this halachah because the gemara says (Yuma 69a) that a cohen gadol is allowed to wear the bigdei kehunah in the beis hamikdash even when he is not performing the avodah .” The Binyan Halacha explains the opinion of the Rambam as follows: Gid hanashe in a korban olah There is a machlokess in Chullin (90a – b) between Rebbi and the Rabbanan whether or not the