The 4 Pillars of Hajj
The Pillars (Arkan) of Hajj are the essential components without which the Hajj is invalid. If a Pillar is missed, the Hajj is void and must be repeated.
1. Ihram
Making the intention and entering the state of purity at the Miqat. It is the spiritual state for performing Hajj.
2. Wuquf at Arafat
Standing at the plain of Arafat on the 9th of Dhul Hijjah from Zawal until sunset. The Prophet (PBUH) said "Hajj is Arafah".
3. Tawaf al-Ifadah
The obligatory circumambulation of the Kaaba performed after returning from Muzdalifah/Mina on the 10th of Dhul Hijjah or days of Tashreeq.
4. Sa’i
Walking seven times between the hills of Safa and Marwah, commemorating the struggle of Hajar (AS).
Difference Between Arkan, Wajibaat, and Sunnah
Arkan: Mandatory. Hajj is void without them.
Wajibaat: Obligatory. If missed, a penalty (Dam/Sacrifice) is required.
Sunnah: Recommended. Rewards are gained, but no penalty if omitted.