What is the reward (mathūbah) in the verse: {Therefore He rewarded you with distress upon distress that you might not grieve for what you missed nor for what befell you; and Allah is All-Aware of what you do}?

Al-Tabari mentioned that the Almighty's saying: "So He repaid you with distress upon distress" means He recompensed you for your fleeing from your Prophet and your disobedience to your Lord with distress upon distress. He called the punishment "reward" (thawab) because it was a recompense for their actions that Allah was not pleased with. So, the recompense (mathubah) here is a requital for disobeying the command of the Messenger, may Allah's prayers and peace be upon him.