Their symbolic stoning of the devil on Thursday will coincide with the Eid al-Azha feast of sacrifice marked by the world’s more than 1.5 billion Muslims.
Around two million white-clad faithful spent a day of prayer Wednesday on a vast Saudi plain for the peak of the Hajj pilgrimage.
Many of the faithful from around the globe had camped at Mount Arafat where they slept and prayed despite the searing temperatures.
Carrying colourful umbrellas, they had walked from dawn in massive crowds towards the 300-metre-high (328 yards) slippery, rocky hill — also known as Mount Mercy — located on the plain, where Prophet Muhammad (P.B.U.H) gave his last sermon 14 centuries ago after leading his followers on Hajj.
Unlike previous years, only a few pilgrims were seen carrying their countries’ flags, in what Saudi media said was a “ban” during the pilgrimage.
The kingdom’s authorities have repeatedly warned against the use of any political slogans or banners during Hajj.
As the faithful gathered in their hundreds of thousands for noon prayers at Arafat, Saudi Arabia’s top cleric, Grand Mufti Sheikh Abdulaziz al-Shaikh, used the opportunity to attack Yemen’s Iran-backed rebels, against whom the kingdom has been leading a military coalition since March.
Most Yemeni pilgrims performing the Hajj this year already reside in the kingdom.
The Huthi rebels at war with Saudi and Gulf troops in Yemen are “a group of criminals,” Sheikh charged in his annual sermon.
As the faithful later began leaving Arafat, police sirens pierced the air as helicopters hovered overhead.
Security officers, heavily deployed along the road, urged walking pilgrims to remain on one side, away from the bus routes as pilgrims headed towards Muzdalifah, where they will remain until dawn.
Other pilgrims use the elevated Mashair Railway linking the holy sites of Arafat, Muzdalifah and Mina — a tent city which will be the final stop for pilgrims and where the stoning ritual occurs.
After that, they circle around the Kaaba in Makkah before heading home at the end of Hajj, which for many is the spiritual peak of their lives.
No major incidents were reported on Arafat but the civil defence agency said there were more than 200 cases of “fainting and fatigue” after doors failed to operate at one of the railway stations, causing crowding.
“We feel blessed. I got goosebumps, a feeling that cannot be explained, when reaching the top of the mountain,” said Ruhaima Emma, a 26-year-old Filipina pilgrim in Arafat, who said she has been “praying for a good life for everyone”.
For Akram Ghannam, 45, from war-torn Syria, being in Arafat is a “feeling that cannot be described. I pray to God for the victory of all those who are oppressed.”
Almost 1.4 million foreign pilgrims are joining hundreds of thousands of Saudis and residents of the kingdom for this year’s Hajj.
They are undeterred by a construction crane collapse at Makkah’s Grand Mosque earlier this month that killed 109 people, including foreign pilgrims.
About 400 people were injured by the crane which was working on an expansion of Islam’s holiest site.
Previously marred by stampedes and fires that killed hundreds, the pilgrimage had been largely incident-free for the past nine years after safety improvements.
The Hajj is among the five pillars of Islam and every capable Muslim must perform it at least once in a lifetime.
This year’s gathering takes place against a backdrop of increased jihadist violence in some Muslim countries, a surge of the potentially deadly MERS virus, in addition to the war in Saudi Arabia’s neighbour Yemen.
About 100,000 police have been deployed to secure pilgrimage sites and manage the crowds.
Authorities say they are on alert for possible attacks by extremists, after Islamic State group jihadists bombed security forces and Shiite mosques in the kingdom in recent months.
Among other challenges facing Saudi authorities is potential transmission of the Middle East Respiratory Syndrome coronavirus (MERS-CoV).
Health officials say there has never been a case of MERS infection among pilgrims.
Hajj began on Tuesday when pilgrims entered Ehraam, a state of purity in which they must not quarrel, wear perfume, or cut their nails or hair.
During Ehraam, men wear a seamless two-piece shroud-like white garment, while women must wear loose dresses, generally also white, exposing only their faces and hands.
“I’m hoping for mercy and that Allah accepts our prayers,” said Pakistani pilgrim Abdeghafour Abu Bakr, 38, who came with friends.