In this manner, the scattered pearls of the Muhaajireen and Ansaar may be threaded into a single strand of brotherhood and become a single entity without any type of disunity and disharmony between them. All of them may hold firmly onto the rope of Allah Ta‘ala, and this ummah should remain completely safe from the dissension and disunity that brought about the destruction of the Banu Israa’eel.
On account of their unity, Allah Ta‘ala’s hand (i.e. special assistance and mercy) would remain over their heads. If, per chance, some evil element of arrogance and pride from the pre-Islamic days still remained within the hearts, then this brotherhood would totally eradicate it. Instead of the heart harbouring pride, arrogance and conceit, the hearts may be filled with humility, meekness, brotherhood and compassion.
The servant and the master, the slave and the owner of the slave, the king and the subjects – all were brought to stand equal on a single platform. All the worldly distinctions were eliminated, and taqwa and piety was made the sole benchmark of nobility and importance. Allah Ta‘ala declares:
إِنَّ أَكْرَمَكُمْ عِنْدَ اللهِ أَتْقٰكُمْ
“Certainly, the most noble among you in the sight of Allah are those who possess the most taqwa.” (Surah Hujuraat v. 13)
It was with these benefits in mind that Rasulullah (sallallahu ‘alaihi wasallam), even before hijrah, established a pact of brotherhood between the Muhaajireen while in Makkah, and after his migration to Madinah Munawwarah, he again established a pact of brotherhood between the Muhaajireen and Ansaar.
Accordingly, this association of brotherhood was launched on two separate occasions. The first was among the Muhaajireen only, whereby one Muhaajir was partnered with another Muhaajir. This took place in Makkah Mukarramah.
The second phase of brotherhood took place in Madinah Munawwarah between the Muhaajireen and Ansaar after the hijrah.
Therefore, Hazrat Ibnu Abbaas (radhiyallahu ‘anhuma) reports that Rasulullah (sallallahu ‘alaihi wasallam) established a pact of brotherhood between Hazrat Zubair (radhiyallahu ‘anhu) and Hazrat Abdullah bin Mas’ood (radhiyallahu ‘anhu), whereas both of them were from the Muhaajireen.
Hazrat Ibnu Umar (radhiyallahu ‘anhuma) reports, “Rasulullah (sallallahu ‘alaihi wasallam) established a pact of brotherhood between Hazrat Abu Bakr (radhiyallahu ‘anhu) and Hazrat Umar (radhiyallahu ‘anhu), between so-and-so and so-and-so… (Hazrat Ibnu Umar [radhiyallahu ‘anhu] then went on to mention a few other Sahaabah)”
Hazrat Ali (radhiyallahu ‘anhu) then enquired, “Who is my brother, O Rasulullah (sallallahu ‘alaihi wasallam)?” Rasulullah (sallallahu ‘alaihi wasallam) replied, “I am your brother.”
(Extracted from Seeratul Mustafa 1/434-436)