According to search-discovered classical Islamic scholarship, the concept of Ajr (الأجر), or Divine Reward, is a foundational principle in the Quran that signifies Allah's guaranteed recompense for faith and righteous deeds. Classical exegetes like Ibn Kathir and Al-Qurtubi, commenting on over 30 key verses, explain that Allah promises never to let the reward of the Muhsinun (doers of good) be lost (Quran 11:115, 18:30). This reward is not merely a transactional payment but a manifestation of Allah's boundless grace and justice, often described as 'great' (adheem), 'noble' (kareem), and 'unending' (ghayru mamnun). The synthesis of verses demonstrates that Ajr encompasses both worldly blessings—such as the wisdom and authority granted to Prophet Joseph (12:56)—and the ultimate reward of Jannah in the Hereafter. This divine promise serves as a core motivator for believers to strive for patience, truthfulness, and excellence in all their actions.