Yoma, Chapter Two, Mishnah Two. In the previous mishnah we learned that at first, in an earlier period, the kohanim would run a race to determine who would win the privilege of removing the ashes, and only if the two runners finished the race together was a lottery needed, by holding out fingers. Our mishnah tells of an incident that occurred and led to a change in the entire system.
The incident that occurred:
"Ma'aseh shehayu shneihem shavin veratzin ve'olin bakevesh" - two kohanim ran side by side. "Shavin" does not mean that they finished the race in a tie, but that they were running neck and neck, and both of them went up the ramp toward the altar.
"Vedachaf echad mehen es chaveiro venafal venishberah raglo" - we cannot know whether the one who pushed intended that his fellow should fall; perhaps he only meant to hold him back a little, as a sort of minor rebuke. In any event, the result was that the kohen fell from the ramp and his leg was broken. A broken leg in those days was a matter of real danger.
The enactment of the court:
Since the court, which bore responsibility for the affairs of the Beis HaMikdash, saw that the matter had led to danger, they enacted that the only way to determine who would win the removal of the ashes would be by lottery - by a payis. It is interesting to consider what was done when there were not many kohanim present; presumably a different method of lottery was required then, rather than holding out fingers.
The four lotteries:
The mishnah concludes and teaches: "Arba peyasos hayu sham" - four lotteries were held in the Beis HaMikdash each day, "vezeh hapayis harishon" - the lottery for the privilege of removing the ashes was the first of them.
Were the four lotteries held on Yom Kippur as well?
The early authorities are divided on this question in a significant dispute. On the face of it, it would seem that they were not held, since all the services on Yom Kippur were performed by the Kohen Gadol. Even though regarding the removal of the ashes, as we mentioned, there may be a dispute as to whether it was performed by the Kohen Gadol, the other services determined by the remaining lotteries were certainly performed by him alone. From here an entire discussion arose: why was the subject of the lotteries brought here in Maseches Yoma, if it has no bearing on Yom Kippur. And there are those who hold that even on Yom Kippur the lotteries had a place in some form.
In summary: in this mishnah we learned how the race for the removal of the ashes was abolished: two kohanim ran neck and neck and went up the ramp, one pushed his fellow and he fell and his leg was broken, and since the court saw that the matter had led to danger they enacted that the winner would be determined only by a lottery. We also learned that four lotteries were held in the Beis HaMikdash each day, and the removal of the ashes is the first lottery, and we noted the dispute among the early authorities as to whether the lotteries were held on Yom Kippur as well.