And the three (per verse 106 - those who stayed behind from war and whose decree was postponed) who were left behind (He accepted their repentance as well). The earth became strait to them in spite of its spaciousness and their souls were also straitened to them. They knew it for certain that there was no refuge but Allah. Then He accepted their repentance that they might redeem their spirits back to Allah again. Surely Allah is the Accepter of repentance, the Most Merciful (the One Who sends the Light of Mercy).
O you who believe (who wish to reach Allah before death)! Be the owners of piety towards Allah and be with the Sâdikîn (loyal ones).
It is not (proper) for the people of Madinah and those surrounding them of the Bedouins that they remain behind after the Messenger of Allah or that they prefer their souls over his soul. This is because there afflicts them not thirst or fatigue or hunger in the Way of Allah, nor do they take any step which enrages the disbelievers, nor do they attain from the enemy what they attain, but an improving deed is written down to them on account of it; surely Allah does not waste the reward of the Muhsînin (good-doers).
Nor do they spend anything that may be spent, small or great, nor do they traverse a valley, but it is written down to their credit, that Allah may reward them with the best of what they used to do.
And it is not necessary for the believers that they should go forth (to fight) altogether. Of every troop of them, a party only should go forth, that they (who are left behind) may get instructions in religion and they may warn their people when they return to them, so that they may beware (of Allah).