Tractate “Yoma”, which is Aramaic for “The Day” (the tractate was also called “Kippurim” or “Yom HaKippurim”), teaches the laws of Yom Kippur. However, seven of the eight chapters of the tractate deal with high priest’s worship in the Temple and only one of the chapters, the last one, deals with the laws of fasting and the issue of atonement. In other words, after the destruction of the Temple only one of these chapters is of immediate halakhic relevance. This is somewhat similar to the previous two tractates we have learned, Pesahim and Shekalim, which also contained large portions pertinent only to a time when the Temple still stood.
The description of the high priest’s worship is found in Leviticus 16:1-34 and we shall make frequent reference to these verses. The Mishnah in large part explicates these verses, although not in a midrashic fashion, following the order of the verses, but rather in “mishnaic” fashion, following the order in which these actions are done.
Interestingly, there are very few debates between different sages in these mishnayot. There are a few but they are mostly concerning the details and some of these concern the sacrificial procedures followed during the remainder of the year and not just on Yom Kippur. Albeck therefore concludes that the core of this tractate is early, and existed when the Temple still stood. It was transmitted by sages in later generation and these sages added in a few of their own comments, but left most of it in the way they received it.
For those of you who pay close attention to the Yom Kippur service, you may remember a section called “Avodah” which is recited towards the end of Mussaf. The description of the high priest’s service described there is based on our Mishnah and on the accompanying Talmud, so when you get to shul (in little more than a month!)—pay attention and note the similarities.