is there any sunni who wanna reason?
Text (nass) of the Designation Then followed the key sentence denoting the clear designation of 'Ali as the leader of the Muslim ummah. The Prophet [s] held up the hand of 'Ali and said: "For whoever I am his Leader (mawla), 'Ali is his Leader (mawla)."
The Farewell Pilgrimage
Ten years after the migration (hijrah), the Messenger of Allah [peace and blessings be upon him and his Progeny] ordered to his close followers to call all the people in different places to join him in his last pilgrimage. On this pilgrimage he taught them how to perform the pilgrimage in a correct and unified form.
This was first time that the Muslims with this magnitude gathered in one place in the presence of their leader, the Messenger of Allah [s]. On his way to Makkah, more than seventy thousand people followed Prophet [s]. On the fourth day of Dhu'l-Hijjah more than one hundred thousand Muslims had entered Makkah.