The gathering of pilgrims on the 9th day of Dhul Hijjah is known as

The gathering of pilgrims on the 9th day of Dhul Hijjah is known as "Wuquf bi 'Arafah." This is an important ritual of Hajj where pilgrims gather at the plain of Arafah, a desert area outside of Mecca, to perform prayers and supplications. It is considered the most important day of Hajj, and pilgrims are required to be present for this ritual to complete their pilgrimage. The purpose of this gathering is to seek forgiveness, repentance, and guidance from Allah. The Prophet Muhammad (peace be upon him) said that this day is a day of forgiveness and that Allah frees more people from Hellfire on this day than any other day.