Surah Ha-Mim as-Sajdah, Footnote 34

This descent of angels need not occur in some perceptible form, such that the believers see them with their eyes or hear their voices with their ears. Although God, glorified is He, does sometimes send angels openly to whomever He wills, generally their descent upon believers—especially in hard times when they are being severely pressed by the enemies of truth—occurs in an imperceptible manner, and their words descend not by striking against the eardrums but into the depths of the heart in the form of tranquility and inner peace. Some commentators have understood this descent of angels to be specific to the moment of death, or the grave, or the plain of resurrection. But if one considers the circumstances in which these verses were revealed, there remains no doubt that the actual purpose of mentioning this matter here is to speak of the descent of angels upon those who strive and risk their lives for the supremacy of the true faith in this present life—so that they may find comfort, so that their courage may be strengthened, and so that their hearts may be reassured with the realization that they are not without help or support, but that God’s angels are with them. Although angels do come to welcome the believers at the moment of death, and they also receive them in the grave (the interim realm of barzakh), and on the Day of Judgment they will likewise remain with them continuously from the very beginning of the resurrection until they reach Paradise—yet this companionship of theirs is not confined to that other realm alone; it continues in this world as well. The flow of the discourse makes clear that just as devils and evil beings are the companions of the followers of falsehood in the struggle between truth and falsehood, so too angels are the companions of the believers. On one side, the companions of the followers of falsehood make their misdeeds appear attractive to them and assure them that the oppression, cruelty, and dishonesty they commit in order to suppress the truth are themselves the means of their success, and that through these very things their dominance in the world will remain secure. On the other side, God’s angels come to the followers of truth and deliver the message that is stated in the verses that follow.