Islamic Studies
The Five Pillars of Islam – First Pillar: Shahadah (Kalimah Tayyibah)
What is the most important ritual/station of Hajj, without which the Hajj is invalid?
Explanation
The Prophet ﷺ said: "Hajj is Arafah." Standing (Wuquf) on the plain of Arafat on the 9th of Dhul-Hijjah is the most critical ritual. Missing it means the Hajj is not valid.
Reference: Five Pillars of Islam Notes
, Page 5