There is no emigration after the conquest (of Makkah)
A'ishah ( May Allah be pleased with her ) narrated that the Prophet (may the peace and blessings of Allah be upon him) said,
"There is no emigration after the conquest (of Makkah) but only Jihad [ (striving and fighting in the cause of Allah) will continue ] and good intention.* So if you are summoned to fight, go forth."
[Al-Bukhari and Muslim]
The migration for the sake of Allah is the focus of the Muslims and their ultimate aspiration in every time and place. They do not neglect it to collect the debris of this world and seeking it diligently, as done by many of those whose money and children make them forget about the remembrance of Allah. They continue to be immigrants in the way of Allah with their own money, with their souls and with their intentions.
Migration is of two types: the migration of the body and the migration of the soul. If you like, you may say: the migration with the deeds, and the migration with the intention.
The migration of the body is of two types: the migration of seeking the reward and closeness to Allah and the second type is emigration from the wrath of Allah.
The migration of the soul is of two types as well: to migrate from the sins to worshipping Allah, and to migrate from Allah to Him, as one can not escape from Allah but to him.
As for the migration before the conquest, it is better than migration after it with no doubt; because it was for spreading Islam and to reach the place from which they start to fight shirk and the idolaters, and to ward off the sedition that is infidelity and misguidance, and because the Muslims who emigrated with the Prophet, may the peace and blessings of Allah be upon him, were the elite of his companions and the best of His men.