סימן רב סעיף א
הַכֹּהֵן מֻזְהָר שֶׁלֹא לְטַּמֵּא לְמֵת. וַאֲפִלּוּ נֵפֶל שֶׁעֲדַיִן לֹא נִתְקַשְּׁרוּ אֵבָרָיו בְּגִידִין, חָשׁוּב מֵת. (אֵךְ אִם הִפִּילָה תּוֹךְ אַרְבָּעִים יוֹם, לָא חָשִׁיב אֶלָּא כְּמַיָא בְעָלְמָא). וְלָאו דַּוְקָא לְמֵת שָׁלֵם, אֶלָּא אֲפִלּוּ לִדְבָרִים שֶׁנִּפְרָשִׁים מִמֶּנוּ, כְּמוֹ דָם וְכַדּוֹמֶה. וְכֵן אָסוּר לִטַמֵּא לְאֵבֶר מִן הַחַי, אִם יֵשׁ עָלָיו בָּשָׂר כָּל כָּךְ, שֶׁאִם הָיָה מְחֻבָּר, הָיָה רָאוּי לְהַעֲלוֹת אֲרוּכָה. וַאֲפִלּוּ לְאֵבֶר שֶׁל עַצְמוֹ, אָסוּר לוֹ לִטַּמֵּא. וְאָסוּר לְכֹהֵן לִכָּנֵס לְבַיִת שֶׁיֵשׁ שָׁם גּוֹסֵס. וְאַף עַל פִּי שֶׁהַגּוֹסֵס הֲרֵי הוּא כְחַי לְכָל דָּבָר וְאֵינוֹ מְטַמֵּא. מִכָּל מָקוֹם עוֹבֵר הַכֹּהֵן עַל לֹא יְחַלֵּל, שֶׁהוּא מֻזְהָר שֶׁיִשְׁמֹר כְּהֻנָּתוֹ שֶׁלֹּא תִתְחַלֵּל, וְשֶׁמָּא יָמוּת זֶה תֵּכֶף.
The Kohein is commanded not to defile himself through any form of contact with the deceased. Even an abortive fetus, whose limbs have not yet been connected with ligamentous tissue, is considered in this regard as a dead body. (If, however, the abortion occurred within forty days from conception, it is considered like water). The dead body need not be in its entirety, for this law applies even to things that have separated from the corpse such as blood and the like. He is also forbidden to defile himself through contact with the severed limb of a living person, if there is enough flesh on it that were it still connected, it would have possibly healed. Even if it is his own limb, he is forbidden to defile himself by touching it. A Kohein is forbidden to enter a house where a person is close to death, and even though a gosseis (dying person) is considered alive with regard to everything else, and he is not considered impure, nevertheless, the Kohein [by entering such a house] violates the command, "You shall not desecrate,"1Leviticus 21:12. A Kohein is forbidden to attend Medical School. See Igros Moshe, Yorah Deiah III 155. for he is commanded to guard his priesthood so that it does not become profaned, and the gosseis may die at any moment.
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.)