Prophet's Tribe, Ahlal Bayt (Family) & Righteous Successors
After Prophet Muhammad ﷺ there is no other companion of his except Ali ibn abi Talib (alaihi salaam) who was considered so great in his merits that many from among Muslims almost worshiped him. Many Muslims think that it was a grave error committed by some early Muslims who were misguided while others till this day continue to follow in their footsteps and nothing more. To realize why Ali ibn abi Talib (alaihi salaam) was the highest ranking companion and most important of prophet's family member one may refer to the example Isa ibn Maryam (Jesus son of Mary) (alaihi salaam). The following verse of the Quran mention miracles done by Isa ibn Maryam (Jesus son of Mary) (alaihi salaam): “I have come to you with a sign from your Lord, that I determine for you out of dust like the form of a bird, then I breathe into it and it becomes a bird with Allah's permission and I heal the blind and the leprous, and bring the dead to life with Allah's permission.” No wonder it was such great miracles such as causing dead people to rise, obviously with the help of Allah ﷻ that caused deviated ones to start worshiping him. The truthful ones saw the honor Allah ﷻ had given Isa (a.s), recognized it but did not worship him and considered him as a servant of Allah ﷻ. Therefore it is always the great and unbelievable acts of a holy person that causes people to assign almost worshipful reverence to them while ignorantly overlooking the boundaries and limits they overstepped in their rights due only for Allah ﷻ.
The Prophet ﷺ told Ali (a.s): “You have the example of Jesus, the Jews hated him so they wronged his mother and the Christians loved him so they raised him above his status (i.e. assigned attributes of God towards him)“, Ali (a.s) once said: “Two individuals will be tortured (in the hereafter) because of me, one who loves me extremely who attributes things to me which do not rightfully belong to me, and a hater who hates me.” It is no doubt that just how holiness and glory of a person earns him followers and lovers who love him to such an extent crossing boundaries set by Allah ﷻ, so these also become the cause of earning bitter enemies who would do whatever to destroy that person. Such destiny befell Ali Ibn Abi Talib (a.s) who confronted both groups during his lifetime as predicted by the Prophet ﷺ. The sabayees i.e. followers of a deviant named Abdullah bin Sabah loved Ali to such an extent where they made him divine and the khawarij hated him to an extent where they martyred him. Unfortunately both types mindsets are still exist among the Muslims.
Distinctions of Ali (r.a) as compared to all other companions of the Prophet:
Born inside Kabah
As per grand mufti of Egypt Muhammad Sayyid Tantawi “May God have mercy upon Ali ibn Abi Talib (r.a). He was born inside the Kabah.” It’s related from authentic sources that while his blessed mother was pregnant and circling the Kabah, she felt labor pain and fell on one of the sides of Kabah which split and she entered inside. It was right at that moment that she gave birth to Ali who was born inside the house of Allah. Abu Abd-Allah Muhammad ibn Abd-Allah al-Hakim al-Nishapuri says, in Mustadrak al-Hakim, in the section Kitaab Maarifatus Sahaaba that the only person that was born in the Kaaba prior to this was Haakim Ibn Hizaam. The Imam states “Narrations came to us by multiple transmissions that Fatimah Bint Asad (mother of Ali) gave birth to Amir al-Mu’mineen Ali ibn Abu Talib (r.a) inside the Kaaba.”
First child to accept Islam
Some of the people of knowledge said that the first to accept Islam amongst men was Abu Bakr As-Siddique; and Ali accepted Islam when he was a boy of eight years; and the first accept Islam amongst women was Khadijah. [Jaami at-Tirmidhi, Volume 6, Chapters on al-Manaaqib (Virtues); page 401, Hadith number 3734] The first child in Islam is Ali ibn Abi Talib (r.a).
Ali's sacrifice for Prophet Muhammad ﷺ
It is recorded in authentic sources of Islamic history including the Prophet's biography that when he was about to make his Hijrah (emigration) to Madinah, he chose to escape in the mid of night, in the darkness because the disbelievers were planning to assassinate him and were closely watching him. At that moment Ali (a.s) volunteered to sleep in the Prophet's bed so the enemies think that it is the Prophet while he makes his escape. Most importantly even though this exposed Ali (a.s) to threat of being killed while sleeping, yet he submitted happily to it.
Ali’s (r.a) reaction to enemy in battle
Once during the battle Ali’s brave skills brought an enemy down on the ground and was about to kill him when the enemy in his anger spat on Ali’s (r.a) face. Right at that moment Ali (r.a) threw his sword and walked away. To the enemy’s astonishment who inquired Ali (r.a) as to why he do that. Ali replied “When I was about to kill you I was fighting for the sake of Allah but when you spat on me, my anger overtook by love of Allah and I wanted to kill you for my own anger’s sake therefore I withdrew immediately.” Amazed at this behavior the enemy accepted Islam.
Miracle at the Battle of Khaybar
Ali (r.a) was known for his exceptional miracles. Among these is what was related from the Prophet who said will give the flag to a man whom Allah and His Messenger love. Allah ﷻ will conquer it by his hands and he will not flee. Each of the three great warriors of the Jews had a duel with Ali (a.s) and he killed all of them quickly to the amazement of everyone. The death of three successive Jew warriors unnerved the Jews and they ran back to shut themselves in the fort. Before the Jews could shut the gate of the fort, Ali struck at the gate and uprooted it. It is said that he tossed the door aside seventy men gathered to return the door back to its place and found it difficult. When inquired about this battle Ali (r.a) would say “I did not snatch the door of Khaybar from its place by bodily power but by divine power.”
Ali’s (r.a) submission to the will of Allah ﷻ
Abdul Rahman ibn Muljam was the man who martyred Ali ibn Abi Talib (r.a). He was one of the Khawarij, a deviant group that rebelled against Ali when he was a caliph. Long time before killing Ali, this man used to walk around and Ali was heard saying “I see my killer”, to which someone inquired “why don’t you catch him and kill him.” to which Ali (r.a) replied “If I kill him then who will kill me?” Later it was this same man who had come in the masjid in Ramadaan on the blessed night of 21st and martyred the Imam.
Prophet compares Ali (r.a) to Prophet Harun (alaihi salaam)
Narrated Saad bin Abi Waqqas (r.a) that the Prophet ﷺ said to Ali, “You are to me, in the position that Harun was to Musa, [except that there is no Prophet after me].” Such distinction was not given by the Prophet ﷺ to anybody around him except Ali (r.a).
Caliph Umar (r.a) bears witness to Ali’s judgments
After Jerusalem came under Muslim, Caliph Umar (r.a) sought Ali’s advice if he should stay in Madinah or visit Jerusalem, to which Ali advised him that he should go. The decisive Muslim victory at Battle of Yarmuk was on the advice of Ali. Umar acted on the advice of Ali, and the Muslims won an astounding victory at the Battle of Yarmuk. Hijrah Muslim calendar was initiated by Caliph Umar (r.a) on the advice of Ali (r.a). In view of the soundness of his judicial opinions, Ali (r.a) was held by Umar (r.a) to be the best judge. At the end of his term Umar (r.a) paid the highest tribute to Ali (r.a) when he said, “But for Ali, Umar would have been lost.” Umar (r.a) was one of the strongest Caliphs that Islam has ever had and he owed a lot of his success to Ali's wisdom.
Prophet chose only Ali (r.a) for continuation of his progeny
The Prophet used to say that the sons of every mother are referred to by their relation to their father except the sons of Fatima (a.s). I am their guardian and they are related to me (as sons). Fatima, the youngest daughter of the Prophet had come of marriageable age, and the Prophet had to consider the question of her marriage. Abu Bakr (r.a) waited on the Prophet, and asked for the hand of Fatima. The Prophet made no answer. Thereafter Umar (r.a) asked for the hand of Fatima and the Prophet maintained silence. In the meantime the Prophet received the revelation that Allah ﷻ approved of the marriage of Fatima (r.a) with Ali (r.a). When the mother of Ali called on the Prophet to press the suit on behalf of Ali (r.a), the Prophet was pleased to announce his acceptance.
Prophet, Ali and the lake of Kauthar
The Kauthar is a river gifted to the Prophet by Allah from which he will quench the thirst of the believers on Judgment day. The only companion with whom he will be distributing water from this river is none but Ali ibn Abi Talib (r.a).
There is no doubt that other companion’s share closeness to the Prophet in their own ways. However none of them can be compared with the status enjoyed by Ali ibn Abi Talib (r.a).
 Al Quran 3:49
 Musnad of Imam Ahmad
MinFada-ilal-‘Ashrat al-Mubashireen bil Janna - https://en.wikipedia.org/wiki/Birthplace_of_Ali_ibn_Abi_Talib
 Chishti, Irshad Soofi Siddiqui. 2010. Madinah to Karbala Holy Blood on Unholy Hands. Abd al-Qadir Soofi Publications
 &  Masud-ul-Hasan, Professor. 1982. " Khalifa Ali bin Abu Talib - The Caliphate of Umar." Alim - The world's most useful Islamic software. Accessed 03 14, 2019. http://www.alim.org/library/biography/khalifa/content/KAL/37/6
 al-Andalusi, Ustadh Luqman. 2012. The Greatness of Caliph Ali ibn Abi Talib. March 20. Accessed March 14, 2019. http://www.muwatta.com/the-greatness-of-caliph-ali-ibn-abi-talib/.
 Mutahhari, Ayatullah Murtada. 2013. Character of Ali Ibn Abi Talib. Islamicmobility.com.
 Jami Tirmidhi Vol. 1, Book 46, Hadith 3730 – Sunnah.com
 Masud-ul-Hasan, Professor. 1982. " Khalifa Ali bin Abu Talib - The Caliphate of Umar." Alim - The world's most useful Islamic software. Accessed 03 14, 2019. http://www.alim.org/library/biography/khalifa/content/KAL/37/6