Tafsir of At-Tawbah 9:124

{And whenever a surah is revealed...}

{Among them are those who say}: Among the hypocrites are those who say to one another: {Which of you has this [surah] increased in faith?}—speaking in denial and mockery of the believers and their conviction that faith increases through the knowledge gained from revelation and acting upon it.

• "Which of you" (أيكم): It is in the nominative case (marfu') as an initial subject (mubtada').
• Ubayd ibn Umayr's reading: He read it with a fatha (accusative), implying a hidden verb explained by the following verb {has increased him}. The estimation is: "Which of you has this [surah] increased?"

{It increased them in faith}: Because it provides more certainty and steadfastness, and brings more comfort to the heart. Or, it means it increased them in deeds, for an increase in deeds is an increase in faith, as faith encompasses both belief and action.

{And it increased them in filth upon their filth}: Meaning disbelief added to their disbelief. For every time God renews revelation, they renew their disbelief and hypocrisy; thus, their disbelief intensifies, becomes firmly rooted, and their punishment is multiplied.

{Do they not see that they are tested every year once or twice? Yet they do not repent, nor do they remember. And whenever a surah is revealed, they look at one another, [saying], "Does anyone see you?" Then they turn away. God has turned their hearts away, for they are a people who do not understand.}