Following his commission, in the thirteen more or less years, which the Holy Prophetsa spent in Makkah, Islām had taken root in the land of Arabia, and its effect had reached outside of Makkah as well. As such, Abū Dharr Ghifārī, ‘Abdullāh bin Mas‘ūd Hudhailī, Ḍimād bin Tha‘labah, Abū Mūsā Ash‘arī, Ṭufail bin ‘Amr Dausī, Sa‘d bin Mu‘ādh Ausī, Sa‘d bin ‘Ubādah Khazrajī, etc. and many such examples of other tribes that converted to Islām in this era are also present. However, there is no doubt that until now, Islām was in a very weak state, and with regards to physical means, its life was not free from danger due to the opposing elements it was forced to confront.
The number of converts from the Quraish of Makkah until the prophetic migration is not fully known, nor have they been mentioned in any narration. However, it can be estimated, by circumstances, that the number of Muslim converts from the Quraish and their associates would not have been more than a hundred souls in any case. Both women and children are included in this number. In other words, the only outcome of the thirteen year endeavor of the Holy Prophetsa within the Quraish of Makkah was these one hundred souls. Furthermore, it has already been mentioned that among these, a significant number of people were those who, due to their young age or poverty, possessed no real influence or power within the Quraish.
Aside from the Quraish, the number of Muslim converts among other tribes, putting the people of Yathrib aside, is very minimal indeed. However, Islām did spread in Yathrib very rapidly, and it can be presumed that prior to the prophetic migration, the total number of Muslims in Madīnah, including women and children, definitely may have reached many hundreds. In this manner, the total number of Muslims up until the migration equals 1000 at most, among whom, if women and children are subtracted, the number of grown men is perhaps no more than 300 to 400. However, after the migration, all of these were not present in Madīnah with the Holy Prophetsa, rather, some were scattered throughout their respective tribes. Some were in Abyssinia, while those who did not yet have the power to migrate were still being victimized by the persecution of the Quraish in Makkah. With this limited man-power, amidst claims of victory, before the critical-eye of world religions, Islām moved forward.