Man through his God-given nature realizes without any doubt that no organized society, such as a country or city or village or tribe or even a household consisting of a few human beings, can continue to subsist without a leader and ruler who puts the wheel of the society in motion and whose will govern each individual’s will and induces the members of that society to perform their social duty. Without such a ruler, the parts of this society become dispersed in a short time and disorder and confusion reign. Therefore, he who is the ruler and governor of a society, whether it be great or small, if he is interested in his own position and the continued existence of his society, will appoint a successor for himself if he is to be absent from his function temporarily or permanently. He will never abandon the domain of his rule and be oblivious to its existence or annihilation. The head of a household who bids farewell to his house and household for a journey of a few days or months will appoint one of the members of the household or someone else as his successor and will leave the affairs of the house in his hands.
In the same way Islam is a religion which according to the Holy Book and the teachings of holy prophet (PBUH) is established upon the basis of the primordial nature of things. It is a religion concerned with social life, as has been seen by every observer near and far. The special attention God and the Prophet have given to the social nature of this religion can never be denied or neglected. It is an incomparable feature of Islam. The Holy Prophet was never oblivious to the problem of the formation of social groupings wherever the influence of Islam penetrated. Whenever a city or village fell into Muslim hands he would, in the shortest time possible, appoint a governor or ruler in whose hands he would leave the affairs of the Muslims. In very important military expeditions ordered for the Holy War (jihad), he would appoint more than one leader and commander, in order of succession. In the war of Mau’tah he even appointed four leaders, so that if the first were to be killed the second would be recognized as the head and his command accepted and if the second were to be killed, then the third, and so on.
The Prophet also displayed great interest in the problem of succession and never failed to appoint a successor when necessary. Whenever he left Medina he would appoint a governor in his own place. Even when he migrated from Mecca to Medina and there was as yet no idea as to what would occur, in order to have his personal affairs managed in Mecca for those few days and to give back to people what had been entrusted to him, he appointed Ali – may peace be upon him – as his successor. In the same way, after his death Ali was his successor in matters concerning his debts and personal affairs. The Shi’ites claim that for this very reason it is not conceivable that the holy Prophet should have died without appointing someone as his successor, without having selected a guide and leader to direct the affairs of Muslims and to turn the wheels of Islamic society.
According to established traditions in both Sunni and Shi’ite collections of hadith transmitted from the holy Prophet, the Prophet foretold seditions and tribulations which would entangle Islamic society after his death, and the forms of corruption which would penetrate the body of Islam, and later worldly rulers who would sacrifice this pure religion for their own impure, unscrupulous ends.
How is it possible that the Prophet (PBUH) should not neglect to speak of the details of events and trials of years or even thousands of years after him, and yet would neglect the condition that had to be brought into being most urgently after his death? Even if we accept the hypothesis that the appointment of the ruler of Islamic society is given by the Islamic laws to the people themselves, still it would be necessary for the Prophet (PBUH) to give an explanation concerning this matter. He would have had to give the necessary instructions to the community so that they would be aware of the problem upon which the existence and growth of Islamic society and the life of religious symbols and observances depended and relied. Yet there is no trace of such a prophetic explanation or religious instruction. If there had been such a thing, those who succeeded the Prophet (PBUH) and held the reins of power in their hands would not have opposed it.
Actually, the first caliph transferred the caliphate to the second caliph by bequest. The second caliph chose the third caliph through a six-man council of which he was himself determined and ordered. Mu’awiyah forced Imam Hasan to make peace and in this way carried away the caliphate. After this, even the caliphate was converted into a hereditary monarchy. Gradually many religious observances identified with the early years of Islamic rule (such as holy war, commanding what is lawful and prohibiting what is forbidden, the establishment of boundaries for human action) were weakened or even disappeared from the political life of the community, nullifying in this domain the efforts of the Prophet of Islam.
Shi’ism has studied and investigated the primordial nature of man and the continuous tradition of wisdom that has survived among men. It has penetrated into the principal purpose of Islam which is to revivify man’s primordial nature, and has investigated such things as the methods used by the Prophet in guiding the community; the troubles which entangled Islam and the Muslims and which led to division and separation; and the short life of the Muslim governments of the early centuries, which were characterized by negligence and lack of strict religious principles. As a result of these studies, Shi’ism has reached the conclusion that there are sufficient traditional texts left by the Prophet (PBUH) to indicate the procedure for determining the Imam and successor of the Prophet (PBUH). This conclusion is supported by Quranic verses and hadiths of Ghadir, Safinah, Thaqalayn, Haqq, Manzilah, Da’wat-i ‘ashirah-i aqrabin and others. But of course these hadiths, most of which are also accepted by Sunnism, have not been understood in the same way by Shi’ism and Sunnism. Otherwise the whole question of succession would not have risen. Whereas these hadiths appear to Shi’ites as a clear indication of the Prophet’s intention in the question of succession, they have been interpreted by Sunnis in quite another way so as to leave this question open and unanswered.
To prove the caliphate of Ali ibn Abi Talib, Shi’ites have had recourse to Quranic verses, including the following: “Your friend [wali] can be only Allah; and his messenger and those who believe, who establish worship and pay the poor-due, and bow down (in prayer) [or, and this reading is accepted by ‘Allamah Tabataba’i: “….pay the poor-due while bowing down (in prayer)”]” (Quran, V, 55). Shi’ite and Sunni commentators alike agree that this verse was revealed concerning Ali ibn Abi Talib, and many Shi’ite and Sunni traditions exist supporting this view. Abu Dharr Ghifari has said: “One day we prayed the noontime prayers with the the Prophet (PBUH). A person in need asked people to help but no one gave him anything, ‘Oh God! Be witness that in the mosque of the Prophet no one gave me anything.’ Ali ibn Abi Talib was in the position of genuflection in the prayers. He pointed with his finger to the person, who took his ring and left. The Prophet (PBUH), who was observing the scene raised his head toward heaven and said, ‘Oh God! My brother Moses said to Thee, “Expand my breast and make easy my tasks and make my tongue eloquent so that they will comprehend my words, and make my brother, Harun, my help and wazir (successor)” [cf. Quran, XXVIII, 35]. Oh God! I am also Thy prophet; expand my breast and make easy my tasks and make Ali my successor and helper.'” Abu Dharr says, “The words of the Prophet (PBUH) had not as yet finished when the verse [cited above] was revealed.”
Another verse which the Shi’ites consider as proof of the caliphate of Ali is this: “This day are those who disbelieve in despair of (even harming) your religion; so fear them not, fear me! This day have I perfected your religion for you and completed my favour unto you, and have chosen for you as religion AL-ISLAM” (Quran, V, 3). The obvious meaning of this verse is that before that particular day the infidels had hopes that a day would come when Islam would die out, but God through the actualization of a particular even made them lose forever the hope that Islam would be destroyed. This very event was the cause of the strength and perfection of Islam and of necessity could not be a minor occasion such as the promulgation of one of the injunctions of religion. Rather, it was a matter of such importance that the continuation of Islam depended upon it.
This verse seems to be related to another verse which comes toward the end of the same chapter: “O Messenger! Make known that which hath been revealed unto thee from thy Lord, for if thou do it not, thou will not have conveyed His message. Allah will protect thee from mankind.” (Quran, V, 67). This verse indicates that God commanded a mission of great concern and importance to the Prophet which if not accomplished would endanger the basis of Islam and prophecy. But the matter was so important that the Prophet feared opposition and interference and in awaiting suitable circumstances delayed it, until there came a definite and urgent order from God to execute this command without delay and not to fear anyone. This matter also was not just a particular religious injunction in the ordinary sense, for to preach one or several religious injunctions is not so vital that if a single one of them were not preached it would cause the destruction of Islam. Nor did the Prophet of Islam fear anyone in preaching the injunctions and laws of religion.
These indications and witnesses add weight to the Shi’ite traditions which assert that these verses were revealed at Ghadir Khumm and concern the spiritual investiture (walayat) of Ali ibn Abi Talib. Moreover, many Shi’ite and Sunni commentators have confirmed this point.
Abu Sa’id Khudari says: “The Prophet (PBUH) in Ghadir Khumm invited people toward Ali and took his arm and lifted it so high that the white spot in the armpit of the Prophet of God could be seen. Then this verse was revealed: ‘this day have I perfected your religion for you and completed my favor unto you, and have chosen for you as religion AL-ISLAM.’ Then the Prophet said, ‘God is great (Allahu Akbar) that religion has become perfected and that God’s bounty has been completed, His satisfaction attained and the walayat of Ali achieved.’ Then he added, ‘For whomever I am the authority and guide Ali is also his guide and authority. Oh God! Be friendly with the friends of Ali and the enemy of his enemies. Whoever helps him, help him, and whoever leaves him, leave him.'”
In summary we can say that the enemies of Islam who did everything possible to destroy it, when they lost all hope of achieving this end, were left with only one hope. They thought that since the protector of Islam was the Prophet, after his death Islam would be left without a guide and leader and would thus definitely perish. But in Ghadir Khumm the Prophet (PBUH) presented Ali as the guide and leader of Islam to the people. After Ali this heavy and necessary duty of guide and leader was left upon the shoulders of his family.
Some of the hadiths pertaining to Ghadir Khumm, the investiture of Ali, and the significance of the Household of the Prophet (PBUH)are cited here:
Hadith-i ghadir: The Prophet of Islam upon returning from the farewell pilgrimage stopped in Ghadir Khumm, assembled the Muslims and after delivering a sermon, chose Ali as the leader and guide of Muslims.
Bara’ says: “I was in the company of the Prophet during the farewell pilgrimage. When we reached Ghadir Khumm he ordered that place to be cleaned. Then he took Ali’s hand and placed him on his right side. Then he said, ‘Am I the authority whom you obey?’ They answered, ‘We obey your directions.’ Then he said, ‘For whomever I am his master (maula) and the authority whom he obeys, Ali will be his master. Oh God! Be friendly with the friends of Ali and enemy of the enemies of Ali.’ Then Umar ibn al-Khattab said to Ali, ‘May this position be pleasing to you, for now you are my master and the master of all the believers.'”
Hadith-i safinah: Ibn ‘Abbas says, “The Prophet (PBUH) said, ‘My household is like the ship of Noah ; whoever embarks upon it will be saved and whoever turns away from it will be drowned.'”
Hadith-i thaqalayn: Zayd ibn Arqam has recounted that the Prophet said, “It seems that God has called me unto Himself and I must obey His call. But I leave two great and precious things among you: the Book of God and My Household. Be careful as to how you behave toward them. These two will never be separated from each other until they encounter me at Kawthar (in paradise).” Hadith-i thaqalayn is one of the most strongly established hadiths, and has been transmitted through many chains of transmission and in different versions. Shi’ites and Sunnis agree concerning its authenticity. Several important points can be deduced from this hadith and it’s like:
(1) In the same way that the Holy Quran will remain until the Day of Judgment, the progeny of the Holy Prophet will also remain. No period of time will be without the existence of the figure which Shi’ism calls the Imam, the real leader and guide of men. (2) Through these two great trusts (amanat), the Prophet has provided for all the religious and intellectual needs of the Muslims. He has introduced his Household to Muslims as authorities in knowledge and has pronounced their words and deeds to be worthy and authoritative. (3) One must not separate the Holy Quran from the Household of the Prophet (PBUH). No Muslim has a right to reject the “sciences” of the members of the Household of the Prophet and remove himself from under their direction and guidance. (4) If people obey the members of the Household and follow their words they will never be led astray.
God will always be with them. (5) The answers to the intellectual and religious needs of men are to be found in the hands of the members of the Household of the Prophet. Whoever follows them will not fall into error and will reach true felicity; that is, the members of the Household are free from error and sin and are inerrant. From this it can be concluded that by “Members of the Household” and “progeny” is not meant all the descendants and relatives of the Prophet. Rather, specific individuals are meant who are perfect in the religious sciences and are protected against error and sin so that they are qualified to guide and lead men. For Shi’ism these individuals consist of Ali ibn Abi Talib and his eleven descendants who were chosen to the imamate one after another. This interpretation is also confirmed by the Shi’ite traditions. For example, Ibn ‘Abbas has said, “I said to the Prophet (PBUH), ‘Who are your descendants whose love is obligatory [upon Muslims]?’ He said, ‘Ali, Fatimah, Hasan and Hussain.'” Jabir has transmitted that the Prophet (PBUH) has said, “God placed the children of all prophets in their ‘backbone’ but placed my children in the backbone of Ali.”
Hadith-i haqq: Umm Salmah has said, “I heard from the Prophet of God who said, ‘Ali is with the Truth (haqq) and the Quran, and the Truth and the Quran are also with Ali, and they will be inseparable until they come upon me at Kawthar.'”
Hadith-i manzilah : Sa’d ibn Waqqas has said, “The Prophet of God said to Ali, ‘Are you not satisfied to be to me what Harun was to Moses except that after me there will not be another prophet?'”
Hadith-i da’wat-i ‘ashirah : The Prophet(PBUH) invited his relatives for luncheon and after the meal told them, “I know of no one who has brought to his people better things than I have brought to you. God has commanded me to invite you to draw toward Him. Who is there who will assist me in this matter and be my brother and inheritor (wasi) and vicegerent (khalifah) among you?” All remained silent, but Ali, who was the youngest of all, exclaimed, “I shall be your deputy and aide.” Then the Prophet put his arms around him and said, “He is my brother, inheritor and vicegerent. You must obey him.” Then the group began to depart laughing and telling Abu Talib, “Muhammad has ordered you to obey your son.”
Hudhayfah has said, “The Prophet of God said, ‘If you make Ali my vicegerent and successor – which I do not think you will do – you will find him a perspicacious guide who will direct you toward the straight path!”
Ibn Marduyah has said that the Prophet (PBUH) said, “Whoever wishes that his life and death be like mine and that he enter paradise should after me love Ali and follow my household, for they are my descendants and have been created from my clay. My knowledge and understanding have been bestowed upon them. Therefore woe unto those who deny their virtues. My intercession [on the Day of Judgment] will never include them.”
So the concept of Imamate, rooted in the revelation of God, is approved in important verses of the Quran, and what’s more, it is rationally based on the reasons mentioned above. God has created humans to give them the opportunity to go through the right path to attain eternal bliss and perfection. That is why He has appointed for us infallible Imams as successors of the last Prophet Muhammad (PBUH) to help us achieve this purpose.