Zamakhshari in his Kashshaf...

Zamakhshari in his Kashshaf, considering the meaning of the following Verse which concerns faith, have interpreted sadd ad hoc in the sense of: “turning away” (i’radh) from faith; however, taking the Qur’anic usage of the word into consideration, the dominant sense of the word is “hindering and impeding.” “Render their deeds vain” is used in the sense that “He” will make their plans ineffective and fruitless, since reducing something serves as a metaphor for being abandoned which necessitates perdition.

At any rate, some exegets take the sentence as an allusion to those who provided people with the meat of the camels slaughtered at the battle of Badr. Abu Jahl, Safwan, and Sahl ibn ‘Amr each slaughtered ten camels as a token of thanksgiving.[^4] Such acts were of no avail with polytheism and satanic stratagems hence their being rendered totally vain. It is not apparently restricted to the sense in question rather all their seemingly good deeds, e.g.

But those who believe and do righteous good deeds, and believe in that which is sent down to Muhammad – for it is the truth from their Lord – He will absolve them of their vices and will make good their state. Having faith is insufficient for availing oneself of Divine Favors rather one has to do good righteous deeds and follow the Messenger of God: (“those who believe and do righteous good deeds and believe in that which is sent down to Muhammad”).

Regarding the Noble Verse in question exegets maintain that: “But those who believe” alludes to the Medinan Helpers (ansar) and “that which” (ma): “in that which is sent down” (bi-ma nuzzila) refers to the Qur’an; in other words the contextual meaning of the clause in question is “those who believed in the Qur’an sent down to Muhammad (S) by God and held that It is true, unchangeable, and standing firm on Its basis to the Last Day and It is not exposed to alterations like other Divine Books, e.g.

the Torah, the Christian Bible, which have been abrogated by the Holy Qur’an.