Imām and the leader of the Muslims who is to succeed the great Prophet assuming the management of the mundane and religious affairs of people must have certain distinctions.
1. He must be free from errors and mistakes to be able to lead the society toward prosperity because an impure person won’t be able to clean up peoples’ contamination.
2. Imām must be in touch with the Unseen and enjoy boundless divine knowledge to be able to explain the Islamic facts, concepts and edicts to Muslims, because if he were to speculate or merely possess ordinary human learning like other people, then his remarks would not be compelling and people won’t appreciate the truth of the Islamic teachings.
3. Imām must be appointed by the great Prophet or his predecessor on behalf of God, because none except God and His Prophet could determine the infallibility of others and people are also unable to be certain about anyone’s future.
Therefore, it is not appropriate to hand over the appointment of Imāms to people because, although people might regard someone as innocent and pure, in actuality, he may be the contrary or people might confirm someone’s integrity in the light of present circumstances but he may lapse into error and impurity in the future.
It is only and merely God who is aware of the present and future and within as well as the without and knows who to choose to lead the society and assume the management after the great Prophet. The great Koran says,
“God knows better to whom He should turn over the religious and mundane leadership of the people.”
Who has been appointed as the successor of the Prophet?
At the command of God, the Prophet of Islam has introduced all of his successors and has explicitly named them, one by one, and has recurrently reminded people of ‘Alī’s right to succession. An examination of history and books will reveal that the Prophet over the twenty-three years of his prophetic mission has raised the subject of the succession of Imām ‘Alī on any propitious occasion. Here, we will only refer to two cases, the first took place at the onset of the prophetic mission and the second occurred during the last year of his life.
1. The prophetic mission and the leadership of Imāms are continuous
Approximately three years after the appointment of the great Prophet, this verse was revealed, “Admonish your close relatives with the threat of divine torment (and invite them to worship God).”
In the exegesis of this verse, the commentators have pointed out that, on the day when the great Prophet was called on by God to invite his close relatives, he asked ‘Alī who was barely fifteen years old to prepare food, then he invited the progeny of ‘Abd al-Muṭṭalib who numbered about forty to announce his mission to them. On that day, Abū Lahab the Prophet’s uncle disrupted the reception with irrelevant remarks.
The great Prophet held another session and after the meal was served announced his invitation and said, “I have been appointed by God and herald the best of this world and the hereafter for you and God has called on me to invite you to His dominion…”
Then, at the same reception the great Prophet observed, “Who among you is ready to stand by me, to be my brother and successor?”
‘Alī rose and voiced his readiness. The great Prophet told him to sit down and repeated his invitation three times. No one answered him except ‘Alī, every time he announced his invitation, then he turned to those who were present and said, “This youth, ‘Alī, is my brother and successor among you, obey him and listen to his remarks.”
This incident, about its authenticity there is no doubt neither in the accounts of the Sunnī nor Shī’ah, clearly demonstrates that the prophetic mission and the leadership of Imāms are not distinct and on the day when the divine Prophet was introduced to people, it is on the same day that his successor should be named and it should be known basically that the foundations of these two positions are the same and they are connected to one another like the links of a chain and the leadership of Imāms is the continuation of the prophetic mission and the successor of the Prophet pursues the same goals as the Prophet but the distinction between them is that the Prophet is the founder of the religion but Imām is its explicator.
The Ḥadīth of Ghadīr
In the last year of his life, the great Prophet who was returning from the Ḥajj pilgrimage stopped at a place called Ghadīr where pilgrims parted from one another. There he mounted a high mound so that he could be seen by everyone whose number amounted to nearly one hundred thousand and at the command of God announced the succession of Imām ‘Alī to that crowd. He held ‘Alī’s hand and raised it so that everyone could observe, and then said, “O folks! Just as I am your leader and decision-maker and have control over your life and property, ‘Alī is also your leader and commander.”
Thus, again it was made clear to everyone that ‘Alī is the immediate successor of the great Prophet and on the same day people offered congratulations to ‘Alī and even ‘Umar told ‘Alī, “Great, you’re my and every Muslim’s leader.”
Indeed, the Prophet of Islam announced Imām ‘Alī’s right to succession again and again so that everyone should know who is the ruler of Muslims after the demise of that revered figure.
Besides these, in the final days of his life, the great Prophet told people, “O folks! I leave you with two priceless things, that is, Koran and my household, so long as you seek these two and follow my legacy, you won’t go astray.”
The Ḥadīth of Jābir
Jābir ibn ‘Abdullāh Anṣārī recounts that when the verse, “Obey God and the Prophet and those who are in authority among you!” was revealed I told the divine Prophet, “O the Messenger of God! We know God and His Prophet and it is important that we know those who are in authority with whom this verse obliges us to comply, could you explain the meaning of the phrase?”
The great Prophet said, “they are my successors and the Imams after me and they begin with ‘Alī ibn Abī Tālib and then respectively, Ḥasan ibn ‘Alī, Ḥusayn ibn ‘Alī, ‘Alī ibn Ḥusayn, Muḥammad ibn ‘Alī who is known as Bāqir in the Bible and you will spend your old age in his leadership and remember me to him when you see him. After Muḥammad ibn ‘Alī, the rest are as follows respectively, Ja‘far ibn Muḥammad, Mūsā ibn Ja‘far, ‘Alī ibn Mūsā, Muḥammad ibn ‘Alī, ‘Alī ibn Muḥammad, Ḥasan ibn ‘Alī, and after him his son who is my namesake and who will dominate the whole world and who will be hidden from the sight of people and whose absence will be protracted that only those who remain steadfast and firm will persist in their belief in his leadership.”
Of course, the accounts pertaining to the successors of the great Prophet are innumerable and we raised these just to exemplify some. Therefore, undoubtedly, the twelve Imāms of the Shī‘ah have been determined by the great Prophet on behalf of God and furthermore, every Imām has explicitly introduced his successor to remove any misunderstanding and doubt on the part of people.
In addition to this, as we noted earlier, Imām must be infallible and connected with the Unseen and after the great Prophet except these twelve figures, innocence has not been verified in any one and no one has been able to present teachings and insights similar to those delivered by these twelve figures. To establish this it suffices to examine Nahj al-Balāghah by ‘Alī and the remarks recorded from other Imāms.
 Sūrah al-An‘ām 6:124.
 Sūrah al-Shu‘arā’ 26:214.
 It has been drawn and abridged from Majma‘al-Bayān, vol. 7, Islāmiyah, p. 206 and al-Mīzān, vol. 15, p. 263 onward and some other books.
 The tale of Ghadīr has been cited in every Shī‘ah and Sunnī book and for more information look at the translation of the first volume of al-Ghadīr.
 There is no doubt about the issuance of this ḥadīth by the great Prophet (peace be upon him and his household) neither on the part of Shī‘ahs nor Sunnīs, for more information consult the translation of Ḥadīth al-Thaqalayn by Shaykh Qawām al-Dīn Wishnawī published in Qum and Tehran.
 Kifāyah al-Athar, first print, p. 7.
 Note: You will read the abridged account of the fourteen infallible figures which is in effect complementary to the discussion of the prophetic mission and the leadership of Imāms after the lesson about the Resurrection.