The Kaaba represents the metaphorical house of God and the oneness of God.
On the Day of Arafat, Muslims recite the Arafah prayer from Zuhr prayer to sunset.
One of the five pillars of the world's fastest-growing religion, the hajj is expected to draw two million people from around the globe this year.
The annual pilgrimage sees the Muslim faithful gather in Mecca, all clad in white, to perform rituals around the black Kaaba cube.
Hajj is a pilgrimage, or journey, that Muslims must make once in their lifetime, as long as they can afford it and are healthy enough. Eid al-Adha, or feast of the sacrifice, begins on Tuesday, when pilgrims begin three days of casting stones at walls in a symbolic renunciation of the devil.
Eid al-Adha also includes the slaughter of sheep, with the meat distributed to Muslims in need.
Saudi Arabia says the Qatari government is using the issue for political ends and it "rejects any effort to politicise the Hajj or drag political differences" into the pilgrimage, the official said, speaking on condition of anonymity.
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Saudi minister of information, Awad Bn Saleh Al-Awad who conducted journalists to the cites reiterated the commitment of the kingdom to conduct a safe and hitch free hajj. King Salman's official title is the "Custodian of the Two Holy Mosques", at Mecca and Medina.
The kingdom has spent billions of dollars of its vast oil revenues on security and safety measures, particularly in Mina, where some of the hajj's deadliest incidents have occurred. Tehran had temporarily suspended sending its citizens to hajj following a 2015 stampede that left around 2,300 pilgrims dead, including hundreds of Iranians.
The interior ministry said on Saturday that the number of pilgrims arriving in Mecca had already surpassed the two million mark, mostly from overseas including large contingents from Egypt, India, Pakistan and Bangladesh.
Meanwhile, Saudi Arabia also faces threats from al-Qaida militants and a local faction of the Islamic State group. "These things do not happen with the security forces in the present world".
The preparatory rituals for Hajj require neither a set time nor do they ask the pilgrim to sleep in a specific place.
Meanwhile, a Saudi-led war in Yemen against Iran-backed Shiite rebels drags on without an end in sight.
Hilal Issa, a 70-year-old from Algeria, said he was praying for God to pardon all Muslims and save the Arab world from its afflictions.