Originally, all the Sahaba (R) had accepted Islam with due thought and understanding and therefore, they were among the category of true Quranic mumins. However, many tribes accepted Islam in masses when Islam had become well-established as a system with rule of law in society. The Quran refers to these people as follows:
The meaning and aspects of Iman from the Quran which sheds light as to why these bedouins should not call themselves mumins. If Allah does not let these bedouins call themselves mumins, who willingly accepted to enter Islam, how can born Muslims call themselves mumins, who did not accept Islam by choice and did not fulfill the requirements of Iman?