And certainly Allah made a covenant with the children of Israel, and We raised up among them twelve chieftains; and Allah said: Surely I am with you; if you keep up prayer and pay the poor-rate and believe in My messengers and assist them and offer to Allah a goodly gift, I will most certainly cover your evil deeds, and I will most certainly cause you to enter into gardens beneath which rivers flow, but whoever disbelieves from among you after that, he indeed shall lose the right way.

It shall be no crime in the weak, nor in the sick, nor in those who do not find what they should spend (to stay behind), so long as they are sincere to Allah and His Messenger; there is no way (to blame) against the doers of good; and Allah is Forgiving, Merciful;

It did not beseem the people of Medina and those round about them of the dwellers of the desert to remain behind the Messenger of Allah, nor should they desire (anything) for themselves in preference to him; this is because there afflicts them not thirst or fatigue or hunger in Allah's way, nor do they tread a path which enrages the unbelievers, nor do they attain from the enemy what they attain, but a good work is written down to them on account of it; surely Allah does not waste the reward of the doers of good;