Mishnayos Nazir Perek 7 Mishnah 1

A High Priest and a nazirite may not become ritually impure even to bury their deceased relatives. However, they become impure to bury a corpse with no one to bury it [met mitzva]. If one of them comes across the corpse of a Jew, and there is nobody else available to bury it, he must bury the body. If a High Priest and a nazirite were walking along the way and they found a met mitzva, and one of them can tend to the burial by himself, Rabbi Eliezer says: Let the High Priest become impure, and do not let the nazirite become impure. And the Rabbis say: Let the nazirite become impure, and do not let even a common priest become impure. Rabbi Eliezer said to the Rabbis: It is preferable to let the priest become impure, as he does not bring an offering for his impurity, and do not let the nazirite become impure, as he brings an offering for his impurity. The Rabbis said to him: On the contrary, let the nazirite become impure, as his sanctity is not permanent, and do not let a priest become impure, as his sanctity is permanent.

כֹּהֵן גָּדוֹל וְנָזִיר אֵינָן מִטַּמְּאִין לִקְרוֹבֵיהֶן, אֲבָל מִטַּמְּאִין לְמֵת מִצְוָה. הָיוּ מְהַלְּכִין בַּדֶּרֶךְ וּמָצְאוּ מֵת מִצְוָה, רַבִּי אֱלִיעֶזֶר אוֹמֵר, יִטַּמָּא כֹהֵן גָּדוֹל וְאַל יִטַּמָּא נָזִיר. וַחֲכָמִים אוֹמְרִים, יִטַּמָּא נָזִיר וְאַל יִטַּמָּא כֹהֵן גָּדוֹל. אָמַר לָהֶם רַבִּי אֱלִיעֶזֶר, יִטַּמָּא כֹהֵן שֶׁאֵינוֹ מֵבִיא קָרְבָּן עַל טֻמְאָתוֹ, וְאַל יִטַּמָּא נָזִיר שֶׁהוּא מֵבִיא קָרְבָּן עַל טֻמְאָתוֹ. אָמְרוּ לוֹ, יִטַּמָּא נָזִיר שֶׁאֵין קְדֻשָּׁתוֹ קְדֻשַּׁת עוֹלָם, וְאַל יִטַּמָּא כֹהֵן שֶׁקְּדֻשָּׁתוֹ קְדֻשַּׁת עוֹלָם: