Sahih Muslim Book 20, Hadith Number 4599.

Chapter : No migration after the conquest of Mecca but allegiance could be sworn (to a rightful leader) on serving the cause of Islam, on fighting in the way of Allah and on following the path of virtue.

‘Aisha reported that the Messenger of Allah (may peace be upon him) was asked about migration, whereupon he said: There is no migration after the Conquest (of Mecca), but Jihad and sincere intention. When you are asked to set out (for the cause of Islam), you should set out,