9:26Then God sent down His serenity upon His Messenger, and upon the believers; and He sent down troops you did not see; and He punished those who disbelieved. Such is the recompense of the disbelievers.

9:111God has purchased from the believers their lives and their properties in exchange for Paradise. They fight in God’s way, and they kill and get killed. It is a promise binding on Him in the Torah, and the Gospel, and the Quran. And who is more true to his promise than God? So rejoice in making such an exchange—that is the supreme triumph.