Imam Ali's Leadership as reflected in Hadith of Manzilat

Introduction
Hadith of Manzilat is one of the most important hadiths discussed among Muslim scholars regarding the issue of Imam Ali's caliphate and leadership [i.e. Imamate]. In terms of authenticity, it is at the peak of validity so much so that Hakim Haskani, a prominent Sunni scholar says, "My teacher Hafiz 'Abdawi has cited five thousand chains of narration for this hadith." 1 This leaves no room for doubt about the authenticity of this hadith.

The Occasions on which the hadith was issued.
It must be noted that the aforementioned hadith was uttered by the Prophet (s.a.w.a) in different occasions, the most important of which was the battle of Tabuk. When the Prophet  (s.a.w.a) was prepared to set out for the battle of Tabuk, for some reason, he left Imam Ali (as) in Medina in order to guard and protect the city. This caused some people to tell Imam Ali (as) he was not worthy of accompanying the Prophet (s.a.w.a). These words saddened Imam Ali (as). Upon Hearing this, the Prophet (s.a.w.a) said to Imam Ali (as), "O Ali, are you not pleased that you are to me as Aron (as) was to Moses (as), except that there will be no prophet after me?" 2

The Significance of Hadith of Manzilat
The importance of hadith of Manzilat can be understood from two points: one is related to the high status attributed to the Imam (as) in the hadith. It is narrated that once Mu'awiyah asked Sa'd ibn Abi Waqqas why he refused to curse Imam Ali (as) to which he responded by mentioning three virtues for the Imam (as) one of which was Hadith of Manzilat. 3

The other point is that by means of this hadith the vicegerency of Imam Ali (as) to the Prophet (s.a.w.a) and his leadership can be clearly proved, for the Prophet (s.a.w.a) gave Imam Ali (as) all the titles that prophet Aron (as) had with regard to prophet Moses(as) with the exception of the position of prophethood because with the appointment of Prophet Muhammad (s.a.w.a) this divine position was sealed.

The shared grounds between Imam Ali (as) and Prophet Aron (as)
So far, we have learned that according to the hadith of Manzilat, Imam Ali (as) has the same position with regards to the Prophet (s.a.w.a) that Aron (as) had with regards to prophet Moses (as). Now, it is time to investigate the position of Aron (as) and the titles he enjoyed in his relation with Moses (as).

It is mentioned in the Quran that when prophet Moses (as) was chosen by Allah, he asked Allah to appoint Aron (as) as his minister and one who would share this task with him and he was granted his wish,

And appoint for me a minister from my family -  Aaron, my brother. Increase through him my strength, and let him share my task, that we may exalt You much. 4

Another point is that before prophet Moses (as) went to receive guidance from Allah which lasted for forty days he left Aron (as) among his people as his successor:

And We made an appointment with Moses for thirty nights and perfected them by [the addition of] ten; so the term of his Lord was completed as forty nights. And Moses said to his brother Aaron, "Take my place among my people, do right [by them], and do not follow the way of the corrupters."

Conclusion
What can be concluded from this short article is that as Aron (as) was the brother of Moses (as), his minister, his successor and the one who shared with him his mission, likewise, Imam Ali (as) was the Prophet's brother, his minister, his successor among the Muslims and the one who assissted him in his divine mission and did not spare any efforts in the way of Allah until the word of Allah was the highest and the word of the disbelievers was the lowest. 

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1. Shawahid al-Tanzil, v. 1, p. 195
2. Sahih Bukhari, v. 4, 1602
3. Sahih Muslim, v. 4, p. 1871
4. The Holy Quran, [20: 29l32]
5. The Holy Quran, [7:142]