Five months after his arrival in Yathirab (the Jathrippa in Ptolemy and Stephan, or Jathrb in Minaean inscriptions. The old word Yathirab is found only once in the Koran, 33:13), now known as Medina, it was Muhammad's next task to find shelter and livelihood for the men who had accompanied him from Mecca. In their own home-town many of them were prosperous, but now they were all equally destitute. As a preliminary step, Muhammad enjoined the Muslims of Medina, now known as Ansar (the helpers) to adopt as brothers their co-religionists from Mecca, now known as Muhajir(the refugees), to share with them like their own kith and kin whatever they possessed, in prosperity and in want. He thus created in Anas's house a bond of brotherhood, known as "Fraternization" (muwakhah), comprising forty-five (or according to another authority, seventy-five) pairs between the Ansars and Muhajirs. This was intended to prove that religion was a firmer basis for brotherly community than membership of the same tribe. These mandates thus resulted in a considerable extension of the Muslim community.
So strong, in short, was this new tie that it surpassed even the relationship of two real brothers.