can a kohen be mochel on his kavod? chiddush of the Chasam Sofer

Can a kohen be mochel on the kavod owed to him? Rambam in Sefer haMitzos #32 writes

היא שצונו לכבד זרע אהרן לפארם ולנשאם ושנשים מדרגתם מדרגה קודמת וראשונה ואפילו ימאנו לא נשמע מהם

Even if the kohen says not to bother, you shouldn't listen.

However, Maharam m'Rutenburg (quoted in the Mordechai) holds that the kohen can be mochel, just like a talmid chacham can be mochel on the kavod due him.

The analogy to a talmid chacham is revealing. The gemara says that a talmid chacham can be mochel because תּוֹרָה דִּילֵיהּ הִיא, it's his honor to do with what he wants, as the pasuk says וּבְתוֹרָתוֹ יֶהְגֶּה יוֹמָם וָלָיְלָה. While Maharam opines that the same is true with respect to a kohen, Rambam writes זה כלו הגדלה לאל יתעלה אחר שהוא לקחם ובחרם לעבודתו ולהקריב קרבנותיו. With respect to a kohen, it's not his honor to forgo.

The Rambam's argument makes logical sense, but there seems to be a gemara against it. The gemara (Git 59b) writes that Chazal made a takana that the kohen always should always take the first aliya. He cannot be mochel, because if he is mochel and doesn't take that aliya a fight is liable to break out in shul as to who should get the honor (nice to see that shuls have not changed much in 1500 years). According to the Rambam, why was a takana necessary? Built into the din d'oraysa is the fact that a kohen cannot be mochel!

This issue of mechila comes up in an incident quoted in the Mordechai in Gittin involving Rabeinu Tam and discussed by many of the poskim: there was a kohen who volunteered to draw water for Rabeinu Tam. R"T was asked how he could accept the favor, as it would be in breach of the mitzvah of honoring the kohen. R"T answered by quoting the din בִּזְמַן שֶׁבִּגְדֵיהֶם עֲלֵיהֶם, כְּהוּנָּתָם עֲלֵיהֶם; אֵין בִּגְדֵיהֶם עֲלֵיהֶם, אֵין כְּהוּנָּתָם עֲלֵיהֶם (Zevachim 17b). When a kohen is not wearing bigdei kehuna, he is like a zar and cannot do avodah. Given that no kohen today wears bigdei kehuna, their status is therefore forfeit. Rabeinu Tam was challenged: if so, can a kohen in our times marry a gerusha?! Can a kohen become tamei?! אֵין בִּגְדֵיהֶם עֲלֵיהֶם, אֵין כְּהוּנָּתָם עֲלֵיהֶם is a din in avodah, not a din in the kohen's status viz kedushas kehuna.  R"T was silent and offered no response. Mordechai goes on to quote R' Peter (interesting name for a Rishon) as defending Rabeinu Tam. The reason R"T had no problem with accepting the kohen's service is because the kohen was mochel on his kavod.

What are we to make of Rabeinu Tam's argument? Rashi on our parsha writes that the din of v'kidashto applies even to a kohen ba'al mum who cannot do avodah. Is a kohen who is not wearing bigdei kehuna worse than a ba'al mum?!

In defense of R"T the Ksav Sofer quotes his father as saying what sounds like a Brisker sevara. There are 2 dinim in kedushas kehuna: 1) an obligation to honor the kohen because of what he does; i.e. because he performs avodah in the mikdash, avodas Hashem on the highest level; 2) an obligation to honor the kohen because of who he is, i.e. the descendants of Aharon deserve kavod. It's like the joke of the guy who comes and begs the Rabbi  to make him a kohen. The Rabbi  refuses, but the man doesn't give up and is insistant.  The Rabbi can't take it and finally asks him, "Why do you want to be a kohen so badly?" To which the man replies, "My father was a kohen, my grandfather was a kohen, so I want to be a kohen." That's the second aspect to v'kidashto. Simply by virtue of being zera Aharon, you have certain privileges.

Nafka mina between these 2 dinin: it's with respect to the first din that the Rambam writes זה כלו הגדלה לאל יתעלה אחר שהוא לקחם ובחרם לעבודתו ולהקריב קרבנותיו. It's by virtue of avodah to Hashem, לעבודתו ולהקריב קרבנותיו, that the kohen deserves honor, and since the honor in the honor of Hashem, it is not subject to mechila. However, with respect to the second din, honor due to the kohen because of who he is, that is within his right to be mochel.

The was the point R' Tam was trying to make. R' Tam's answer goes hand in hand with what R' Peter said -- it's one answer in two parts. You have to first get past the first din of kavod that stems from the kohen's avodah, the honor that is non-negotiable, before you can begin to talk about mechila. That din, said R"T, is not in play because a kohen without bigdei kehuna cannot do avodah. Once that is out of the way, you can talk about the honor due to the kohn personally because of his lineage.  Even a kohen who is a baal mum, a kohen who cannot do avodah, still gets kavod, but that honor is subject to mechila, which was R' Peter's follow up.

This approach is meduyak in the language of the pasuk in our parsha וְקִ֨דַּשְׁתּ֔וֹ כִּֽי־אֶת־לֶ֥חֶם אֱלֹקיךָ ה֣וּא מַקְרִ֑יב קָדֹשׁ֙ יִֽהְיֶה־לָּ֔ךְ כִּ֣י קָד֔וֹשׁ אֲנִ֥י ה׳ מְקַדִּשְׁכֶֽם. There are two halves to the din. קִ֨דַּשְׁתּ֔וֹ כִּֽי־אֶת־לֶ֥חֶם אֱלֹקיךָ ה֣וּא מַקְרִ֑יב, kedusha that stems from the kohen's obligation to do avodah, but then there is an additional element: קָדֹשׁ֙ יִֽהְיֶה־לָּ֔ךְ, irrespective of avodah.

Coming back to the Rambam, perhaps when the Rambam writes that a kohen cannot be mochel he was speaking only about a kohen who can do avodah, in which case both dinim are in play. However, post churban, when we no longer have kohanim b'avodasam, even Rambam would agree that a kohen can forgo his honor. The gemara in Gitin is a post-churban takana, and therefore does not pose a problem for the shitas haRambam.