סימן רב סעיף יא
מֻתָּר הַכֹּהֵן לִטַּמֵּא לַקְּרוֹבִים, וּמִצְוָה לוֹ לִטַּמֵּא לָהֶם. וְאֵלּוּ הֵן הַקְּרוֹבִים: אִשְׁתּוֹ הַרְאוּיָה לוֹ (שֶׁאֵינָהּ פְּסוּלָה לוֹ), אָבִיו וְאִמוֹ, בְּנוֹ וּבִתּוֹ, וְאָחִיו וַאֲחוֹתוֹ מֵאָבִיו שֶׁהָיוּ בְּנֵי קַיָמָא. אֲבָל לְסָפֵק נְפָלִים, אֵינוֹ מִטַּמֵּא (וְעַיֵּן לְקַמָּן סִימָן ר"ג סָעִיף ג). וְאֵינוֹ מִטַּמֵּא לַאֲחוֹתוֹ שֶׁנִּתְקַדְּשָׁה לְאִישׁ. יֵשׁ אוֹמְרִים הָא דְמֻתָּר וּמִצְוָה לִטַּמֵּא לַקְּרוֹבִים, דַּוְקָא לְצֹרֶךְ קְבוּרָה אוֹ לְהָבִיא לוֹ אָרוֹן וְתַכְרִיכִין וְכַדּוֹמֶה. וְלָכֵן בַּשַׁבָּת שֶׁאִי אֶפְשָׁר לְקָבְרוֹ בּוֹ בַיוֹם, אָסוּר לִטַּמְּאוֹת לוֹ אֲפִלּוּ כְּדֵי לְשָׁמְרוֹ, וְנָכוֹן לְהַחְמִיר כֵּן. מִיהוּ לְצָרְכֵי קְבוּרָה, וַדַּאי מִצְוָה לִטַּמֵּא לָהֶם. וַאֲפִלּוּ יֵשׁ חֶבְרָא קַדִּישָׁא הַמִּתְעַסְּקִים וְהוּא אֵינוֹ מִתְעַסֵּק כְּלָל, מֻתָּר לוֹ לִהְיוֹת שָׁם בַּבַּיִת, שֶׁמָּא יִצְטָרְכוּ לְאֵיזֶה דָבָר. וְאֵינוֹ מִטַּמֵּא לַקְּרוֹבִים אֶלָּא עַד שֶׁיִסָּתֵם הַגּוֹלֵל וְלֹא אַחַר כָּךְ.
A Kohein is permitted to defile himself at the death of his relatives, and it is a mitzvah for him to do so. These are the relatives for which he may defile himself: his wife whom he was permitted to marry, his father, his mother, his son or his daughter, his brother and sister born from his father, provided they were born full term, but for a child who may have been aborted, a Kohein may not defile himself. He may not defile himself for a married sister.2Even if she was divorced or widowed and no longer married. Some Poskim maintain that which a Kohein is permitted and is a mitzvah to defile himself for relatives is only for the needs of burial, or to bring a coffin, or shrouds, or the like. Consequently, on Shabbos, a day when he may not be buried, a Kohein is forbidden to defile himself even in order to guard the deceased. It is proper to follow this strict opinion. However, concerning things necessary for burial, it is certainly a mitzvah for him to defile himself. Even if there is a Burial Society to take care of all the arrangements, and he has nothing to take care of, he is permitted to be in the house in case they might need something. He may defile himself for these relatives only until the grave is closed, and not thereafter.
תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)