Аль-Анфаль 8:73

Generally when a man helps another, it is because that other person belongs to his family or group or class. But after the hijrah (migration to Madinah) the Islamic society formed in Madinah was such that those who were householders gave their houses to people with whom their relation was based only on religion. The people who left their hearths and homes and migrated to Madinah had done all this for the sake of God and the Hereafter, and those who allowed these strangers to share their money and property also did so, in order that God should be pleased with them and send them to paradise in the Hereafter. This was a society in which relations of family or race were not important as compared to faith. People used to help each other, not for worldly benefit, but for the sake of the Hereafter. They used to give to each other without expecting any return from the receiver, but only expecting a reward from God. That society is truly Islamic where relations are established not on the basis of family relations or the prejudices of groupism, but on the basis of Truth; where the people are the supporters and helpers of each other for the sole reason that they are brothers in religion and not because some worldly consideration is linked with them.