Exegesis of the saying of Allah the Exalted: ((So that Allah may reward the truthful for their truthfulness))

Allah Mighty and Majestic said: This lam is for causation, meaning that the matter occurs regarding both fulfillment and breach. Fulfillment is by whom? By the believers. And breach is by the hypocrites. This occurred And if people did not differ in their deeds, they would not differ in the reward. And if they did not differ in the reward, there would be no benefit in the creation of Paradise and the Fire. For this reason, Allah the Exalted said: [Hud: 119] So Allah Mighty and Majestic is Wise; He created Paradise and created its inhabitants, and He created the Fire and created its inhabitants. The inhabitants of these two must have deeds that they perform so that they deserve to be among the people of them. And His saying: The ba here is for causality, not for exchange, because the reward for deeds is not a matter of exchange, but rather a matter of linking the effect to its cause, as the Prophet (peace and blessings be upon him) said: So righteous deeds are causes. Otherwise, if Allah Mighty and Majestic had intended to exchange with us for our deeds in the sense of exchange, then if He had compensated us with a single favor from His favors upon us, it would not have compensated for all our deeds, and it would not have compensated for all our deeds. But rather, deeds are a cause. His saying: If the reward is for truthfulness, then it will be according to that truthfulness. So those who were truthful in what they covenanted with Allah, their reward will be for their truthfulness according to what they performed. If they were more obedient to Allah Mighty and Majestic, more diligent in executing His commands, and more active in His obedience, their reward would be greater. And the opposite is the opposite.