The Holy Prophetsa was shown a vision that one day he would have to leave Makkah and migrate to another place, and along with this, he was also shown the place of his migration, which was a place of orchards and springs. The full interpretation of this vision had not yet revealed itself to the Holy Prophetsa, and prior to an explanation, a prophet can also be mistaken in his interpretation of a situation. It is due to this reason that the Holy Prophetsa said:
ذَھَبَ وَھْلِیْ اِلیٰ اَنَّھَا الْیَمَامَةُ اَوْ حَجَرُ فَاِذَا ھِیَ مَدِیْنَةُ یَثْرَبَ
Meaning, “My thought led me to believe that this place would be Yamāmah or Ḥajar (which are two verdant places), but it turned out to be Yathrib.”1
As such, when Islām began to find popularity in Yathrib, it was then that the Holy Prophetsa understood that his place of migration would be Yathrib, and not Yamāmah or Ḥajar. After the meeting with the Anṣār had taken place and they had returned after a Bai‘at was taken in a defensive treaty and pact, the Holy Prophetsa instructed the Muslims that, “All of those who are able, should migrate to Yathrib.” Therefore, after a short time period, despite the many obstructions setup by the Quraish, a majority of the Muslims migrated, and many homes in Makkah were abandoned. Finally, only the Holy Prophetsa, Ḥaḍrat Abū Bakrra, Ḥaḍrat ‘Alīra, their families, or those weak people who were unable to migrate, or those who the Quraish prohibited from leaving, were left behind. All of these Muḥājirīn stayed as guests in various homes belonging to the Anṣār in Madīnah, and remained as such until the Holy Prophetsa himself arrived to Madīnah and separate homes could gradually be arranged for the Muhājirīn. The people of Madīnah, who are referred to as the ‘Anṣār’ on account of their helping and giving protection to the Muhājirīn of the Holy Prophetsa, welcomed the Muhājirīn very passionately and treated them greater than their own brothers. As such, when the Holy Prophetsa migrated to Madīnah, he found all the Muhājirīn full of praise for the Anṣār.2
1 Ṣaḥīḥ Bukhārī, Kitābu Manāqibil-Anṣār, Bābu Hijratin-Nabīsa
2 * As-Sīratun-Nabawiyyah, By Abū Muḥammad ‘Abdul-Malik bin Hishām, pp. 332, 339, Bābu Dhikril-Muhājirīna ilal-Madīnah, Dārul-Kutubil-‘Ilmiyyah, Beirut, Lebanon, First Edition (2001) - (A summary)
* Sharḥul-‘Allāmatiz-Zarqānī ‘alal-Mawāhibil-Ladunniyyah, By Muḥammad bin ‘Abdul-Bāqī Az-Zarqānī, Volume 2, pp. 89-93, Bābu Hijratil-Muṣṭafā wa Aṣḥābihī ilal-Madīnah, Dārul-Kutubil-‘Ilmiyyah, Beirut, Lebanon, First Edition (1996) - (A summary)
* Tārīkhul-Khamīs, By Ḥusain bin Muḥammad bin Ḥasan Dayār Bakrī, Volume 1, p. 320, Dhikru Hijratil-Aṣḥābi ilal-Madīnah, Muwassasatu Sha‘bān, Beirut