Eating on Yom Kippur at the Beis HaMikdash Dedication
At the inauguration of the first Beis HaMikdash the nation feasts even on Yom Kippur, fears punishment, and a Heavenly voice promises them the World to Come.
ט׳
From the article
The Gemara says that when the first Beis Hamikdosh was completed, the Jewish nation rejoiced for seven days. One of those seven days was Yom Kippur. Yet based on the counsel of the sages, they even ate and drank on Yom Kippur. However, they were nevertheless nervous that they would be punished for this infraction until a Heavenly voice proclaimed, “You will all merit the World to Come!” Further, the Gemara notes that all who participated in the festivities merited to have a baby boy that year.