|Positive Mitzvah Thirty-Seven
Kohanim Being Defiled For Deceased Relatives
Scripture forbids Kohanim, out of respect, to defile themselves for the dead, but permits them to defile themselves for relatives.
The Sifra says, "For her he may be defiled" is a Positive Mitzvah. If the Kohen does not wish to defile himself he is made to do so against his will. It happened to Yosef HaKohen that his wife had died on the eve of Pesach, and he refused to defile himself for her, whereupon the Sages employed force and caused him to become defiled against his own will.
The obligation of the Kohen to defile himself for his deceased relatives does not apply to women of Priestly families; for the Kohen, who is forbidden to defile himself for non-relatives, is commanded to suffer defilement for relatives, but the woman of Priestly family is not forbidden to defile herself for any dead person, as I will explain in the proper place, (N166) and is consequently not commanded or obliged to suffer defilement for deceased relatives. She has to observe mourning, but whether to suffer defilement depends on her own wishes.