AGADAH: Rav Yehudah said in the name of Rav that when multitudes of Jews
would crowd into the Beis ha'Mikdash during each of the Shalosh Regalim, a
miracle occurred. When they stood in the Azarah, they were crowded, but when
they bowed down, they had plenty of room. The Gemara says that this is one
of the ten miracles which occurred in the Beis ha'Mikdash.
RAV YONASAN EIBESHITZ (Ahavas Yonasan) explains this miracle as follows. The
Gemara in Berachos (6a), in a discussion about Shedim, says that at the
periodic public lecture prior to the festivals, at which many people
gathered to learn about the Halachos of the upcoming festival, the crowded
feeling that was experienced was due to the presence of Shedim.
The Gemara in Kidushin (29b) relates that there was a certain Shed, which
had the appearance of a seven-headed serpent, terrorizing the Beis
ha'Midrash. Rav Acha went into the Beis ha'Midrash, and when the Shed
attacked him, he bowed down to Hashem in prayer. When he bowed down, one
head of the Shed fell off. He bowed seven times until the seven heads of the
Shed had fallen off and the Shed was dead. From there we see that one way to
destroy Shedim is by bowing down to Hashem.
The crowded feeling the Jews felt during Regalim in the Beis ha'Mikdash,
like the crowded feeling during the gatherings to teach the Halachos of the
Regalim, was due to Shedim. However, when the people bowed down to Hashem,
their acceptance of Malchus Shamayim caused the (momentary) destruction of
the Shedim, eliminating the crowded feeling! (Cited by EINEY SHMUEL)