Source: Saheeh Al-Bukhari. Pg. # 1025, H # 4170.
Verily, those who believed, and emigrated and strove hard and fought with their property and their lives in the cause of Allah as well as those who gave (them) asylum and help, these are (all) allies to one another. And as to those who believed but did not emigrate, you owe no duty of protection to them until they emigrate, but if they seek your help in religion, it is your duty to help them except against a people with whom you have a treaty of mutual alliance; and Allah is the All-Seer of what you do
Holy Qur'aan (8.72)
And there is also a share in this booty for the poor emigrants, who were expelled from their homes and their property, seeking bounties from Allah and (His) good pleasure, and helping Allah and His Messenger. Such are indeed the truthful. And (it is also for) those who, before them, had homes and had adopted the faith, love those who emigrate to them, and have no jealousy in their breasts for that which they have been given, and give them preference over themselves even though they were in need of that. And whosoever is saved from his own greed, such are they who will be the successful. And those who came after them say: "Our Lord! Forgive us and our brethren who have preceded us in faith, and put not in our hearts any hatred against those who have believed. Our Lord! You are indeed full of kindness, Most Merciful
Holy Qur'aan (59.8-10)