Advice to migrate and the Promise of Provision and a Goodly Reward

Allah commands His believing servants to migrate from a land in which they are not able to establish Islam, to the spacious earth of Allah where they can do so, by declaring Allah to be One and worshipping Him as He has commanded. Allah says:

يَعِبَادِىَ الَّذِينَ ءَامَنُواْ إِنَّ أَرْضِى وَاسِعَةٌ فَإِيَّاىَ فَاعْبُدُونِ

وَالَّذِينَ آمَنُوا وَعَمِلُوا الصَّالِحَاتِ لَنُبَوِّئَنَّهُم مِّنَ الْجَنَّةِ غُرَ‌فًا تَجْرِ‌ي مِن تَحْتِهَا الْأَنْهَارُ‌ خَالِدِينَ فِيهَا (And those who believe and do righteous deeds, We shall accommodate them in mansions of the Paradise beneath which rivers flow, where they will live forever - 29:58).

The other risk involved in hijrah (migration) is about the arrangement of sustenance in the strange land. One does manage the sustenance at one's own place through employment, trade, cultivation, or inherited land, but on migration all that is left behind. So, how would he manage the sustenance in the new environment? Answer to this apprehension is given in the next three verses by saying that you regard the mundane possessions and arrangements as the cause of your sustenance, but who has given you all this? It is your mistake to consider that you have arranged it all on your own. Without the help and will of Allah nothing could be procured. If He wills, one gets unlimited sustenance without any visible means, and if He does not, then despite all sorts of visible means, one does not get anything. For elaborating this point first it is said: