Raising their hands to the sky, about 2 million Muslim pilgrims prayed for salvation Wednesday at Mount Arafat (search), where Saudi Arabia's top cleric said the greatest test for the nation of Islam comes from its sons who are "lured by the devil," a reference to violent Muslim militants.

Many pilgrims' eyes welled with tears as they prayed on the most critical day of the hajj (search ), the annual pilgrimage the faithful believe will wipe away their sins.

While speaking at a mosque on the plain of Mount Arafat, Sheik Abdul-Aziz al-Sheik, the kingdom's grand mufti, referred to the violent campaign waged by Muslim militants affiliated with the Al Qaeda (search) terror network against targets in the kingdom, attacks Saudi authorities have been battling the past two years.

Al-Sheik said the greatest test for the Muslim nation is its own sons gone astray, and he warned them not to be used by enemies of the nation to weaken it.

"The greatest affliction to strike the nation of Islam came from some of its own sons, who were lured by the devil," he said. "They have called the nation infidel, they have shed protected blood and they have spread vice on earth, with explosions and destruction and killing of innocents."

He pointedly asked of Muslim youth: "How would you meet God? With innocent blood you shed or helped shed?"

Al-Sheik also said that campaigns were being waged against the people of Islam — "military campaigns, thought campaigns, economic campaigns, and media campaigns.

"They are all against this religion. The nation was described as a terrorist nation, that we are terrorists and backward," he said. "Conferences have been held and conspiracies have been woven ... all unjustly and unfairly."

Al-Sheik urged worshippers to abide the words of God and his prophet and not be "fooled by a civilization known for its weak structure and bad foundation."

Pilgrims held hands out for each other to climb the gentle yet rugged hill, while many already atop pushed and shoved to hug a pillar, standing where Islam's 7th century prophet Muhammad gave his last sermon.

"Oh God, have mercy on us. Oh God, forgive our sins," Syrian pilgrim Abdul Razzah Hamadah said in prayer with tears in his eyes.

Muhammad delivered his last sermon at Mount Arafat, 12 miles southwest of Mecca, on March A.D. 632, three months before he died.

"God has brought us here and he will take care of our safety," said Hamadah, who accompanied his mother, when asked about security and safety concerns during the pilgrimage. In recent decades, the hajj has been marred by stampedes.

Helicopters hovered above the plain, dotted by pilgrims all the way to the peak of Mount Arafat. Men and women, otherwise not allowed to mix in the conservative kingdom, rubbed shoulders and stretched helping hands to each other as they climbed the uneven slope.

Some pilgrims paused on top of Mount Arafat to photograph the occasion.

There, men in seamless white robes and women, covered from head to foot except for their hands and faces, held prayer booklets and recited the Quran. Pilgrims streamed into the area atop buses and cars crawling along bumper-to-bumper from the sprawling tent city of Mina.