Creating a sea of white robes, more than 2 million Muslims stood in prayer Monday in 100-degree heat at Arafat, the mount overlooking Mecca where the Prophet Mohammed delivered his last sermon 14 centuries ago.

The annual pilgrimage, or hajj, to Mecca so far has been incident-free, unlike previous years that were marred by fires and stampedes, and the Saudis have gone out of their way to keep it that way.Helicopters hovered over the throng, and ambulances stood by to assist anyone overcome by heat or emotions. The Saudis also set up mistmaking machines along the route to Arafat to try to cool down the pilgrims.

The ritual Monday marks the climax of one of the most sacred days of the Islamic calendar.

The pilgrims - all in seamless white robes symbolizing purity - chanted in unison: "O God, I answered your call. . . . There is no God but you."

The 2.3 million pilgrims, who came from about 100 countries, began making their way to Arafat on Sunday from Mina, a tent city on the plains outside Mecca. Many carried umbrellas to protect themselves from a scorching sun.

Some pilgrims, in a display of piety, made the 9-mile journey on foot. But most were ferried in hundreds of buses and cars. Thousands of Saudi policemen directed the crowds.

Every able-bodied Muslim who can afford the trip must perform the hajj at least once in a lifetime. It is an observance packed with symbolism and ritual that is one of the cornerstones of the Islamic faith.

On arriving in Mecca, the pilgrims circle the Kaaba, a cubic stone structure inside the Grand Mosque and Islam's holiest site. Muslims turn toward the Kaaba five times daily to pray.

The day at Arafat is spent reading the Koran, the Muslim holy book, and praying.

In a sermon at Arafat, Abdel-Aziz ben Ali al-Sheik, the imam of the Grand Mosque in Mecca, decried Muslim extremism.

"Extremism is the fruit of ignorance and misconception."