Tafsir of Al Imran 3:148

(So Allah gave them) – meaning, because of their saying that, as indicated by the Fa (conjunction of consequence) – (the reward of this world), meaning victory and spoils of war, as stated by Ibn Jurayj. Qatadah said: It means conquest, dominance, establishment, and victory over their enemy. It has been said that naming this a "reward" is because it is consequent to their obedience, and therein is an honoring and magnifying of them. It has also been said that naming it a reward is metaphorical, as it mimics it.

Ibn Jurayj’s interpretation was problematized by the fact that spoils of war were not lawful for anyone before Islam; rather, when the prophets would acquire spoils, a fire would descend from the sky and consume them. How then could the spoils be a worldly reward when the victors did not receive any of it? The response is that the wealth the fire would consume was non-living, whereas livestock would remain for the victors, not for the prophets—peace be upon them—and that was the worldly reward.

(And the good reward of the Hereafter) – meaning the good reward of the Hereafter, which, according to Ibn Jurayj, is the pleasure of Allah Almighty and His mercy, and according to Qatadah, is Paradise. Specifying the "good" with this reward is to indicate its virtue and distinction, and that it is what is truly counted with Him, Almighty. Perhaps the worldly reward was mentioned first in consideration of the chronological order of occurrence, or because it is more appropriate to what preceded it regarding the supplication for victory over the disbelievers.

(And Allah loves the doers of good) – A supplementary sentence confirming what preceded it, for Allah’s love for the servant is the origin of all good and happiness. The definite article (al) in "the doers of good" (al-muhsinin) is either for reference (referring to the previously mentioned group), where a noun is placed in the position of a pronoun to indicate that what was recounted of them is a form of ihsan (doing good), or it is for the generic category, and they are included in it in a primary sense. In both cases, there is an encouragement for the believers to acquire the noble virtues that were recounted.