وَمَن كَفَرَ فَلَا يَحْزُنكَ كُفْرُهُ ۚ إِلَيْنَا مَرْجِعُهُمْ فَنُنَبِّئُهُم بِمَا عَمِلُوا ۚ إِنَّ اللَّهَ عَلِيمٌ بِذَاتِ الصُّدُورِ (23)
(31:23) So let the unbelief of the unbeliever not grieve you. *43 To Us is their return and then We shall inform them of all that they did. Surely Allah knows well even the secrets that are hidden in the breasts (of people).
*43) This means to say, "O Prophet, the one who refuses to listen to you, thinks that by rejecting Islam and insisting on unbelief he has harmed you, but in fact he has not harmed you but harmed only himself. If he does not listen to you, you need not bother yourself about him at all. "