What is "Kodashim" referring to?
It is referring to the Chazeh v'Shok (the chest and the right calf of the Shelamim and the Todah and to the cooked right foreleg of the ram of the Nazir, which were all given as a gift to the Kohen from the owner.
Why does the Torah see fit to mention that a Ba'al-Mum may even eat Kodshim Kalim? Why is it not a Kal va'Chomer from Kodshei Kodshim?
Rashi: Had it not written Kodshim Kalim, we would have confined the concession to Kodshei Kodshim, which were once eaten by a Zar 1 - Moshe during the seven days of the Milu'im.
Rashi: A concession that we never find by the Chazah v'Shok of Kodshim Kalim. Divrei David - Zevachim 101b says that Moshe was considered a Kohen Gadol. Tana'im argue about this; some say that he was a Zar.
QUESTIONS ON RASHI
Rashi writes that Moshe ate from Kodshei Kodoshim, i.e. the [Shelamim ram of] the Milu'im. What is the source that it was Kodshei Kodoshim?