Shemini, Vayikra 10:4. Tuma in the Mikdash.

 Moshe commanded his nephews to take out the bodies of Nodov and Avihu.  Rashi brings from the Medrash Rabbah here that this was “shelo le’arveiv es hasimcha.

My brother in law, Harav Yosef Asher Weiss, asked, what’s the hechreich that this was the reason?  The most obvious explanation was to remove the tumah from the Mishkan!  My mechutan, Harav Mordechai Jofen, said that there is no proof that it is assur to leave a meis in the Machaneh Shechina, only that it is assur to bring it in.  This is not logical to me, because besides the issur of ‘velo yitam’u’, there is the din in Parshas Nasso of ‘viyishalchu min hamachaneh,’ which clearly is a din on Beis Din to make sure there is no tumah in a makom kadosh.  I know that that din says ‘kol tzorua vechol zov,’ but how can it be that Beis Din is only metzuva to get the people who are tomei out, and not the objects which are tomei?!  Anyway, the Mishna and the Gemorah in Eiruvin 104b say klor that there is a chiyuv to remove an object which is tomei from the Beis Hamikdosh, not like Motti.  So Yosef Asher’s question remains unresolved.
(I do have to admit that Reb Leizer Silver famously used the Sifri Zuta that seems to say that a dead human body is not Tamei, but causes Tumah in other things, to be mechadeish just like Motti, namely, that it is not assur to leave a dead body in the Mikdash.  But at least Reb Leizer Silver had the Sifrim Zuta, and also he would have to deal with the Mishna in Eiruvin.)

 I mentioned the question to Rabbi Dovid Zupnick Senior (Za'l, he was one of the Chashuvei hatalmidim from the Mir, a close friend of Rav Wolbe, with whom he tried to create a yeshiva in Switzerland.)  The next morning he told me the teretz, which, as usual, was so obvious that it made asking the question embarrassing.  The passuk says to take them away from the kodesh ‘el michutz lamachaneh.’  A meis is muttar in machaneh Leviah, and certainly in machaneh Yisroel.  Why el michutz lamachaneh?  In order to not be me’arvev the simcha.  As Rashi says, milifnei hakallah, and Yisroel was the kallah— beyom chasunaso ubeyom simchas libo.

My brother in law, HaRav Moshe Faskowitz, pointed out that in Shemos 24:11, it says that Nodov and Avihu and the Zkainim had a nevua of the image of Hashem, and it says “vayechezu es ho’elokim vayochlu vayishtu,” and it says that “lo sholach yado,” Rashi brings a Medrash that they deserved misa for the irreverence of “vayochlu vayishtu,” but Hashem held back from punishing them until later.  The Medrash says that Hashem held back “shelo le’arveiv es hasimcha.”  So it’s ironic that there was an irvuv simcha by the other most joyous event, the hakomas hamishkan (yom chasunaso veyom simchas libo.)  He toldl me a pshat which I don’t remember completely, but the idea was that the chet they did now needed immediate reaction despite Hashem’s demonstrated unwillingness to punish under such circumstances.