According to Mouood, quoting by Erfan.ir:
Brief facts about Ghadir Event
Ghadir literary means small lake or pond. Ghadir is the name of a place that comes on the way from Makkah to Medina.
It is 3 miles further than Johfa towards Medina. There existed a small pond at this place. Though geographically it exists on the way to Medina but this place acted as an exit point for all the people going out from Makkah for all the other places.
When the Holy Prophet (s.a.w.a.) halted at this place after his last pilgrimage to make his all-significant announcement it was extremely hot at that time and it was close to mid-day. It was a wayside tract of barren land. There was no shelter present over there at that time. In fact there existed merely small minor patches of shades provided by a few acacia trees.
Date of event
The date is 18th Zilhajjah of the year 10 A.H. (10 March 632 CE)
The Holy Prophet (s.a.w.a.) asked his companions to call the Muslims in general to attend for a pilgrimage to the Holy Kaaba. The Holy Prophet (s.a.w.a.) specified that he himself would also be there to attend for the pilgrimage and teach the Muslims the rituals of the pilgrimage and convey his significant messages directly to all. The call for the pilgrimage was made.
On his way to Makkah more than 70,000 Muslims joined him. By the fourth of Zilhajjah more than 100,000 Muslims had collected for the Haj with the Holy Prophet (s.a.w.a.).
After the Last pilgrimage
After completing the last pilgrimage the Holy Prophet (s.a.w.a.) along with the Muslims set out of Makkah. On their way back the Muslims reached a place called Ghadir-e-khumm. The following verse was revealed to the Holy Prophet (s.a.w.a.).
“O Apostle! Deliver what has been sent down to you from your Lord; and if you don’t do it, you have not delivered His message (at all); and Allah will protect you from the people…”
Delivery of the sermon
On receiving the above verse, the Holy Prophet stopped at that very place called Ghadir-e-khumm. He ordered his companions to call back those of the Muslims who had gone ahead. He waited for those Muslims who had remained behind to join them.
He ordered Salman (a.r.) to prepare for a pulpit with the help of rocks and camel toolings. It was prime noontime and Muslims had tied their heads and legs on account of the heat. Muslims had started to sit near the temporary pulpit. The Holy Prophet (s.a.w.a.) was at this place for about 5 hours. He recited nearly 100 verses of the Holy Quran most of which were in the praise of Ali (a.s.). Seventy three times he reminded and admonished the Muslims about their”s deeds and future.
The following is a part of the lengthy speech of the Holy Prophet(s.a.w.a.) which has also been narrated by the sunni authorities repeatedly:
“It seems the time has approached when I shall be called away (by Allah swt) and I shall answer that call. I am leaving for you two precious things and if you adhere to them BOTH, you will never go astray after me. They are the Book of Allah and my Progeny, that is my Ahlul Bayt. The two shall never separate from each other until they come to me by the Pool (of Paradise).”
Then the Holy Prophet (s.a.w.a.) in an attempt to remind Muslims of his own authority over them said:
“Do I not have more right over the believers than what they have over themselves?”
Muslims answered unanimously “Yes, O’ Messenger of God.” This served as a stepping stone for the announcement of his heir and vicegerent. The Holy Prophet (s.a.w.a.) held out the hand of Ali (a.s.) and said:
“For whoever I am his Leader (mawla), ‘Ali is his Leader (mawla).”
The Holy Prophet then continued to say:
“O’ God, love those who love him, and be hostile to those who are hostile to him.”
Revelation of the verse 5:3
Once the Holy Prophet(s.a.w.a.) completed his speech this verse of the Holy Quran was revealed to him:
“Today I have perfected your religion and completed my favour upon you, and I am satisfied that Islam be your religion.”
This verse explicitly mentions that only along with this express announcement of the vicegerancy by the Holy Prophet (s.a.w.a.) can the religion of Islam be considered as complete and perfect. Without this announcement or because of the disregard of this announcement the religion of Islam will be be incomplete & a half truth.
As indicated earlier many a times half truths are more dangerous than full falsehoods. Hence there is no doubt that ,if the Muslims disregard this announcement, they will have to endure oppression and hardship both materially and spiritually.