The gates of the Bais Hamikdash were swallowed in the ground. The descendants of Korach rejoiced when they heard this. They believed that: ‘Whoever extracts the gates from the ground, will extract them as well.’

The Gates of the Bais Hamikdash received special protection from Hashem since they honored the Aron and publicly displayed Hashem’s forgiveness for Dovid Hamelech.

Moshiach personally erects the doors of the third Beis Hamikdash. Sources:

Gemara Kiddushin 31 B

Commentery of Rashi: ‘Istayeya Milsa’

Commentery of Tosafos: Istayeya Milsa

Eicha Perek 2 Possuk 9

Medrash Rabba Eicha Parsha 2 Perek 13

Gemara Sanhedrin 107 B

Likkutei Sichos Volume 11 Page 98, footnote 61

Irin Kadishin Hasholen (Purim page 127)