Avot295

11:
We have arrived at the last three items in the list of miracles in our present mishnah.

People stood crowded but had enough room to prostrate themselves. Our mishnah is referring to the people who daily crowded into the Women's Courtyard. When we studied Tractate Tamid we presented a picture of this courtyard. It can be seen here. This was the main courtyard of the Bet Mikdash and it was here that the people congregated. We should note the massive doors at the top of 15 steps which barred any view from the Women's Courtyard of the Priests' Courtyard and what was being done there. When the time came for prostration a signal was given and everyone in the courtyard prostrated themselves. All our mishnah is saying is that even when the courtyard was very crowded there was always enough room for everyone to make their obeisance.

12:
Now this does not seem to be particularly miraculous. Crowds do seem to find room for what they want to do. Maybe this consideration is what prompted Rabbi Ovadyah of Bertinoro, in his commentary on our present mishnah, to offer an explanation that has no basis whatsoever in the text, and seems merely to serve further to enhance the item's miraculous nature. He says:

13:
No person ever said to someone else, "There is no room for me to stay the night in Jerusalem." The reference is, of course, to the great festivals, when the population of Jerusalem swelled beyond all proportion. For Passover and Tabernacles, the main pilgrimages, the population of the city could treble and more. Those who could not find lodgings would camp out in the streets. Indeed, it was miraculous that every pilgrim found somewhere where he could stay at these times. Of course, at these times the city was so crowded that the situation could become very dangerous – as is illustrated by the concern of the government, both Jewish and Roman, that the arrest and trial of Jesus of Nazereth (at Passover time) not develop into an uncontrollable riot.

14:
The High Priest never had a seminal emission on Yom Kippur. On the Day of Atonement the High Priest was the central – indeed, the sole – ritual functionary. Upon the High Priest fell the awesome religious duties of the day. An emission of semen, even involuntary, would disqualify the High Priest from functioning on that day since he would not be able to ritually cleanse himself (in a Mikveh) until after dark that evening. It was for this reason that the Temple authorities took several precautions. The Mishnah [Yoma 1:1] informs us that

The word 'home' in this context is a euphemism for 'wife'. The High Priest was not permitted marital relations for seven days before Yom Kippur.

15:
It is this last point that tells us that there was, indeed, at least one occasion when the High Priest was disqualified because of a seminal emission during the night! The historian Titus Flavius Josephus, in his history of the Jewish people [Antiquities of the Jews, 17:6] tells us that towards the end of the reign of King Herod, in the year 6 BCE, on the morning of Yom Kippur the High Priest, Matityahu ben-Theophilos, reported that during the night he had a dream in which he had marital relations with his wife, and as a result of this dream he had ejaculated involuntarily. Josephus, rather gleefully, points out that it was for this reason that one Yosef ben-Ellimos became "High Priest for one day".

16:
This historical reference, of course, casts a great doubt on the accuracy of the claim in our mishnah. Indeed, it would seem to suggest that most, maybe all, of the claims in our present mishnah are just a pious "terminological inexactitude".