Their palms facing the sky, around two million Muslims yesterday gathered on Saudi Arabia's Mount Arafat for the highlight of the hajj pilgrimage, one of the world's largest annual gatherings.
With temperatures pushing 40 degrees Celsius (104 Fahrenheit) under the desert sun, the faithful climbed the hill east of Makkah where Muslims believe the Prophet Mohammed (pbuh) gave his last sermon some 14 centuries ago.
The second day of the hajj -- a five-day pilgrimage which all Muslims must perform at least once in their lifetime if physically and financially able -- is dedicated to prayer and reflection.
"I came up here last night and prayed, took pictures and called my family and friends," said Maolana Yahia, 32, who made the trip from Indonesia.
This year's hajj has seen the return of pilgrims from Saudi Arabia's arch-rival Iran following a diplomatic row and a deadly stampede in 2015.
But thousands who would normally make the journey from neighbouring Qatar are absent apart from a few dozen because of the diplomatic crisis shaking the Gulf.
Helicopters flew around the area as the pilgrims converged from dawn on the Mount Arafat plain and the hill known as Jabal al-Rahma, or Mount of Mercy.
Forming a sea of white, the pilgrims ascended the hill and took up positions to pray on rocks already heated by the morning sun.
On the concrete pathways linking the plain to the hill, hundreds of thousands of devout Muslims invoked God, as others rested in makeshift tents or on sheets along the side of the road amid empty bottles and waste.
Tunisian mother-of-three Fatima Arfawi said she was moved beyond words.
"This is the first time I see anything like this, ever," she said. "This day is dedicated to prayer for my three children and my family."
In a hospital opposite the mountain, an area was set aside for people suffering dehydration or heat exhaustion.
Saudi Arabia's Red Crescent said it had deployed 326 ambulances along the pilgrimage route to handle health emergencies.
"Some pilgrims, for example, forget to protect their heads with an umbrella when they pray," said Bandar Al-Harthi, a nurse at a hospital facing Mount Arafat.