We have already explained the proofs testifying to the Ima-mate of Ahl al-Bayt (`a) and the number of caliphs from among them as stated by the Prophet who indicated that they should be his successors in his nation. Following are proofs regarding the appointment by the Prophet of Ali ibn Abu- Ta-lib (`a). In addition to the above, there are unequivocal proofs testifying to the same, especially to the hadi-th of the two weighty things.
Among the most famous narratives regarding the caliphate of Ali (`a) is the one known as the sermon of al-Ghadi-r after the conclusion of the Farewell Pilgrimage (Hijjatul-Wada-`) in 11 A.H. (632 A.D.) It was there and then that the Prophet declared to the people stating, at its conclusion, as narrated by al-Tirmidhi who relies on the isna-d traced to Zaid ibn Arqam, the following: “To whosoever I have been the master, Ali henceforth is his master, etc.”[1]
Ibn Majah has included in his Sahi-h a portion of this detailed sermon through isna-d traced to al-Bara-` ibn `A-zib who said, “We accompanied the Messenger of Alla-h during his pilgrimage. He alighted at a distance of the road and ordered congregational prayers to be held. Then he took the hand of Ali, peace be upon him, and said, `Do not I have more rights on the Muslims than the Muslims themselves have?` They answered in the affirmative. Then he said, `Do not I have right over every believer more than he himself has?` They answered in the affirmative. He then said, `This [Ali] is the master of whoever accepted me as his master. Lord! Be the friend of anyone who befriends him, and be the enemy of whoever antagonizes him.`”[2]
It exists in the Musnad of Ahmad ibn Hanbal who relies on the isna-d of also al-Bara-` ibn `A-zib. The latter says, “We were in the company of the Messenger of Alla-h on a trip. We stayed at Ghadi-r Khumm. We were called upon to perform congregational prayers. A couple of trees were swept under for the Messenger of Alla-h who performed the noon prayers then took the hand of Ali, peace be upon him, and said, `Do not you know that I have more rights on the believers than the believers themselves have?` They answered in the affirmative. He asked them, `Do not you know that I have more rights on every believer than the believer himself has?` They answered in the affirmative. He then took Ali, peace be upon him, by the hand and said, `To whomsoever I have been the master, Ali [henceforth] is his master. O Lord! Befriend whoever befriends him and be the enemy of whoever antagonizes him.` `Umar ibn al-Khatta-b met him thereafter and said to him, `Congratulations to you, O son of Abu- Ta-lib! You have received the dawn and the sunset as the master of every believing man and woman.`”[3] This hadi-th is famous as the “Ghadi-r hadi-th” on account of this incident taking place at an area known as “Ghadi-r Khumm” (Khumm swamp) which is located near Mecca. This is something the authenticity of which nobody can doubt especially since it has been narrated in many Sunni books of hadi-th, so much so that some scholars have stated as many as 80 venues for it only from the Sunnis.
It becomes clear from the previous traditions that the Messenger of Alla-h extracted the Muslims` admission of his mastership over them when he asked them, “Do not you know that I have more rights on the believers than the believers themselves have?... Do not you know that I have more rights on every believer than the believer himself has?” It is understood that anyone who enjoys the status of having more authority over the believers than the believers themselves have is the believers` leader as was, indeed, the Messenger of Alla-h : a leader. When he included Ali (`a) besides himself in such a description by saying, “To whomsoever I have been the master, Ali [henceforth] is his master,” he practically bestowed upon Ali (`a) the leadership after his own demise.
Shi-`ahs celebrate this occasion every year on the 18th of Dhul-Hijjah which they call “Eid al-Ghadi-r.” As for the Sunnis, they interpret this hadi-th differently, claiming it does not refer to any caliphate. They interpret the word “mawla” [which exists in the original Arabic text] as “loved one” or “friend,” not “wali amr,” person in charge. In their view, the meaning of this tradition is: “Anyone whose friend I am, this Ali is his friend, too”!!! The fact is that the word “mawla” has many meanings in Arabic. It is said that it has seventeen meanings including “one who is emancipated” or “servant,” etc. The word “mawla” in this hadi-th is to be understood, besides what is stated above through many proofs, to connote leadership. Among such proofs are the following:
1. The verse saying, “O Messenger! Deliver what has been revealed to you from your Lord, and if you do not do it, then you will have not delivered His message (at all), and Alla-h will protect you from the (evil) people” (Qur`a-n, 5:67) which was revealed, as stated in many books of tafsi-r, shortly before the Ghadi-r sermon. It contains the sense that there is an order from Alla-h Almighty that has to be conveyed, and this order, as the wording of the verse suggests and from its very sharp tone, is of an extreme significance, point in the direction that what is meant is not mere friendship and support.
2. The verse saying “This Day have I perfected your religion for you, completed My favor upon you, and have chosen Islam for you as your religion” (Qur`a-n, 5:4) was revealed, according to many scholars of exegesis, after the Ghadi-r incident. It conveys the completion of conveying Muhammad`s message, something which could not have been completed without the appointment of Ali (`a) and Ahl al-Bayt (`a) in general as the masters. It is far-fetched to say that the conveying became complete when the Messenger of Alla-h was told about his friendship with and love for Ali (`a)!
3. The circumstances during which the Prophet delivered the Ghadi-r sermon, in a burning desert, after having ordered the Muslims, who were said to have numbered more than ninety thousand, to assemble in order to extract from them an admission that Alla-h and His Messenger were their masters before ordering them to accept the mastership of Ali (`a) proves that the matter was not relevant to merely loving and befriending Ali (`a).
4. The previous aha-di-th, especially the one about the Two Weighty Things, in addition to the following ones, point as a whole to the caliphate of Ali (`a) without permitting any room for doubt.

Additional Proofs for Ali`s Caliphate
In al-Tirmidhi`s Sahi-h, relying on the isna-d of `Imra-n ibn Hasi-n, the latter says, “The Messenger of Alla-h dispatched an army under the command of Ali ibn Abu- Ta-lib (`a). The campaign was carried out, and Ali (`a) won a female captive as his share of the booty. Some people faulted him for doing so. Four of the companions of the Messenger of Alla-h pledged to complain against him to the Prophet . With signs of anger on his holy face clearly visible, the Messenger of Alla-h said to them, “What do you want from Ali? Ali is from me, and I am from Ali, and he is the master of every believer after me.”[4] And consider the following verse of the Almighty: “Your Master is Alla-h and His Messenger and the Believers who uphold prayers and pay zakat even while prostrating (Qur`a-n, 5:58).” Most Sunni scholars of exegesis have stated that it was revealed in honor of Ali (`a) when he gave his ring by way of charity, as he was prostrating during his performance of the prayers, to a poor man. In al-Bukha-ri`s Sahi-h, Mis`ab ibn Sa`d quotes his father saying, “The Messenger of Alla-h marched out to Tabuk after having left Ali (`a) behind. Ali (`a) said to him, `Are you going to leave me with the children and the women?` He said to him, `Are you not pleased that your status to me is like that of Aaron to Moses except there shall be no prophet after me?`”[5] This tradition proves that Ali (`a) had all the positions occupied by Aaron, peace be upon him, among the Children of Israel with the exception of prophethood and which is explained by the Almighty, Praise and Exaltation are His, in these verses: “`And give me a minister from my family, Aaron, my brother. Add to my strength through him, and make him share my task: So that we may celebrate Your praise without stint and remember You without stint: For You are He Who (ever) regards us.` (Alla-h) said, `Your prayer is granted, O Moses!`” It is clear from these verses that Aaron, peace be upon him was a vizier of Moses, a special aide and a partner in leading the nation.
What emphasizes this lofty status in his appointment as the caliph of the nation is that he was the most knowledgeable among all the saha-bah according to what al-Bukha-ri narrates from `Umar ibn al-Khatta-b . Ibn `Abba-s has said, “`Umar said, `The one who recites the Qur`a-n the best is my father, while the most judicious among us is Ali.”[6] One who is the most knowledgeable of the injunctions and the laws, as is well known, is the one who makes the best judge. Suffices to prove that he is the most knowledgeable among all the companions and the most wise is that he was the gate of the city of knowledge of the Messenger of Alla-h . In Mustadrak al-Sahi-hayn, relying on the isna-d of Ibn `Abba-s, the Messenger of Alla-h said, “I am the city of knowledge and Ali (`a) is its gate. Whoever seek knowledge has to approach through the gate.”[7] In al-Tirmidhi`s Sahi-h, the Messenger of Alla-h is quoted as having said, “I am the city of wisdom and Ali is its gate.”[8] In Mustadrak al-Sahi-hayn, it is stated that the Messenger of Alla-h said to Ali (`a), “You must explain to my nation after me anything wherein they differ.”[9] The Messenger of Alla-h even made the mark of hating Ali (`a) as one of the indications of hypocrisy as is clear from the narrative included by Muslim in his Sahi-h with its isna-d to Ali (`a) who said, “By the One Who split the seed and created the breeze, it is a covenant from the Ummi Prophet to me that none loves me except a believer (mu`min) and none hates me except a hypocrite.”[10]
Even if the Prophet did not appoint a successor after him, is not the nation supposed to choose the one who has the most knowledge and with the most distinctions in order to be its leader? We have already clarified that Ali (`a) was the most knowledgeable among the companions. They used to refer to him whenever they confronted a complex theological problem. Similar to this is included by Abu- Dawud in his isna-d to Ibn `Abba-s who said, “`Umar brought a mentally retarded woman who had committed adultery. He consulted some people in her regard. `Umar ordered her stoned. Ali ibn Abu- Ta-lib (`a) passed by her and inquired about her. He was told that she was a mad woman by so-and-so who had committed adultery, so she was ordered to be stoned. He told them to take her back. Then he went to him [to `Umar] and said to him, `O `Umar! Don`t you know that judgment against three categories of people is lifted: the mad person till he recovers, the one sleeping till he wakes up and the child till he attains mental maturity?` He said, `Yes.` Ali (`a) said, `Then what is the matter with this woman that she should be stoned?` `Umar said, `Nothing.` She was sent back. `Umar kept making takbeer.”[11] Al-Bukha-ri, too, includes part of the same incident in his own Sahi-h.[12]
Moreover, Ima-m Ali (`a) was famous as the “Ima-m of the ascetics” and he was also famous for his courage and extra-ordinary daring feats. He was the first commando in Islam. In every Islamic battle, he played a decisive role on the side of the Messenger of Alla-h . In the Battle of Badr, he killed with his sword, Sayf al-Fiqa-r, thirty Qurayshite heroes. In the battles of Uhud and Hunayn, he undertook a historic stand, jeopardizing his own life in defense of the Messenger of Alla-h following the flight of the vast majority of the saha-bah! In the Battle of Khandaq (moat), he stood to duel the giant of the polytheists, namely `Amr ibn Wudd al-`A-miri whom he killed at the time when none of the other saha-bah dared to face him although the Messenger of Alla-h had three times called upon them to do so. He finally permitted Ali (`a) to face the man although Ali (`a) was quite young compared to most saha-bah. In the battle for Khaybar, Alla-h granted victory at his hands, so he was able to open the gate of the fort after the Muslims at the time could not do so. A large number of the saha-bah failed collectively to open it.
Ima-m Ali (`a) distinguished himself from the other saha-bah by the fact that the time of ja-hiliyya did not pollute him with its idols. He received his unique upbringing at the hands of the First Teacher of Humanity, Muhammad , from whom he did not part for one moment as long as the Prophet lived. When the Prophet passed away, Ali (`a) was tending to him. He, therefore, remained all his life receiving knowledge and wisdom from the Messenger of Alla-h . Hence, he deserved to be the gate of the city of knowledge of the Prophet , of his wisdom, and his brother. Al-Bukha-ri narrates in his Sahi-h, relying on the isna-d of Abdulla-h ibn `Umar saying, “The Prophet established ties of fraternity among his companions. Ali (`a) came with tearful eyes and said, `O Messenger of Alla-h! You have established ties of fraternity among your companions but did not establish a tie of fraternity between me and anyone else.` The Messenger of Alla-h said, `You are MY brother in the life of this world and in the Hereafter.`”[13] The Prophet even considered Ali (`a) as being of him as al-Bukha-ri has narrated: “The Prophet said to Ali (`a), `You are of me, and I am of you.`”[14]
Ali (`a) distinguished himself from the rest of the saha-bah by acquiring the most merits as we are told by al-Ha-kim in his Mustadrak where he quotes Ahmad ibn Hanbal saying, “None among the companions of the Messenger of Alla-h acquired as many virtues as Ali son of Abu- Talib (`a).”[15] And in Kanz al-`Umma-l, the Messenger of Alla-h is quoted as having said, “Alla-h ordered me to marry Fa-timah (`a) off to Ali.”[16] This happened after having rejected the offer of marriage from a number of the saha-bah who sought her hand in order to earn the great honor of marrying a lady who was “part” of the Messenger of Alla-h , the Head of the Believing Women and of the residents of Paradise, the lady because of whose anger Alla-h would be angry. It is quite true what one said: “Had Ali (`a) not been created, Fa-timah (`a) would have had no match for marriage.”[17]
Having stated all the above, had the selection of the caliph been truly in the hands of the people, Ali (`a) was the most distinguished among the saha-bah, hence he was the most deserving of the caliphate.

Notes:
[1]Al-Tirmidhi, Sahi-h, Vol. 2, p. 298.
[2]Ibn Ma-jah, Sunan, Vol. 1, p. 43, in a chapter about the distinction of Ali ibn Abu- Ta-lib (`a) (published by Da-r Ihya-` al-Tura-th al-`Arabi).
[3]Ahmad, Musnad, Vol. 4, p. 281.
[4]Al-Tirmidhi, Sahi-h, Vol. 2, p. 297.
[5]Al-Bukha-ri, Sahi-h, Vol. 5, p. 492, the book of military campaigns.
[6]Ibid., Vol. 6, p. 10, in the book of exegesis.
[7]Mustadrak al-Sahi-hayn, Vol. 3, p. 126.
[8]Al-Tirmidhi, Sahi-h, Vol. 2, p. 299.
[9]Mustadrak al-Sahi-hayn, Vol. 3, p. 122.
[10]Muslim, Sahi-h, in the book of ima-n, in a chapter about loving Ali (`a), Alla-h glorified his countenance, one of the dignitaries, Vol. 1, p. 262 (Da-r al-Sha`ab edition).
[11]Ibn Dawu-d, Sunan, in a chapter about a mad person stealing or being penalized according to the Shari-`a.
[12]Al-Bukha-ri, Sahi-h, the book of warriors, in a chapter about a mad man or woman should not be stoned.
[13]Al-Tirmidhi, Sahi-h, Vol. 2, p. 299.
[14]Al-Bukha-ri, Sahi-h, Vol. 5, p. 43, in the book of the virtues of the saha-bah.
[15]Mustadrak al-Sahi-hayn, Vol. 3, p. 107.
[16]Kanz al-`Umma-l, Vol. 13, hadi-th 37753. Dhakha-`ir al-`Uqba.
[17]Al-Mana-wi, Kunooz al-Haqa-`iq. It is also recorded by al-Daylami.