﴿ وَنُنَزِّلُ مِنَ ٱلْقُرْءَانِ مَا هُوَ شِفَآءٌۭ وَرَحْمَةٌۭ لِّلْمُؤْمِنِينَ ۙ وَلَا يَزِيدُ ٱلظَّٰلِمِينَ إِلَّا خَسَارًۭا ﴾

“THUS, step by step, We bestow from on high through this Qur'an all that gives health [to the spirit] and is a grace unto those who believe [in Us], the while it only adds to the ruin of evildoers:”

(And We reveal of the Qur'an) We explain in the Qur'an (that which is a healing) a clarification against blindness; it is also said that this means: a clarification against disbelief, idolatry and hypocrisy (and a mercy) which prevents from chastisement (for believers) in Muhammad (pbuh) and in the Qur'an (though it increase the evil-doers) the idolaters; that which is revealed in the Qur'an increases them (in naught save ruin) loss.