As we have seen, it is customary each morning to recite the Mishnayot of the fifth chapter of Masechet Zevahim – Ezehu Mekoman – which goes through all the various sacrifices, explaining the procedure for offering them and their basic laws. By reading and learning about the Korbanot (sacrifices), we earn credit as though we actually brought them in the Bet Ha'mikdash
Intuitively, we might assume that this chapter should not be recited on Shabbat and Yom Tob. The only Korbanot which may be offered on Shabbat and Yom Tob are those which are specifically required on those days – namely, the daily Tamid sacrifice, and the Musaf offerings required on particular occasions. Seemingly, then, we should not recite Ezehu Mekoman, which speaks of sacrifices such as voluntary offerings and offerings required for atonement, as these were not allowed to be brought in the Bet Ha'mikdash on Shabbat.
In truth, however, these Mishnayot are recited on Shabbat. Although they cannot be recited in lieu of the actual offering of the sacrifices, they are nevertheless recited as Torah study. Shabbat is a time to devote additional time for Torah learning, so there is certainly good reason to include the recitation of Ezehu Mekoman on Shabbat, despite the fact that the sacrifices it discusses are not offered on Shabbat.
Ashkenazim have the practice to recite on Shabbat after the Ketoret section the verses from the Torah discussing the Shabbat Musaf sacrifice. Similarly, on Rosh Hodesh, they recite the verses that discuss the Musaf sacrifice brought on Rosh Hodesh. However, the Arizal taught that the verses about the Musaf sacrifice should not be recited, and indeed, our custom is to omit this recitation from the Korbanot section.