أَلَمۡ تَرَ إِلَى ٱلَّذِينَ نُهُواْ عَنِ ٱلنَّجۡوَىٰ ثُمَّ يَعُودُونَ لِمَا نُهُواْ عَنۡهُ وَيَتَنَٰجَوۡنَ بِٱلۡإِثۡمِ وَٱلۡعُدۡوَٰنِ وَمَعۡصِيَتِ ٱلرَّسُولِۖ وَإِذَا جَآءُوكَ حَيَّوۡكَ بِمَا لَمۡ يُحَيِّكَ بِهِ ٱللَّهُ وَيَقُولُونَ فِيٓ أَنفُسِهِمۡ لَوۡلَا يُعَذِّبُنَا ٱللَّهُ بِمَا نَقُولُۚ حَسۡبُهُمۡ جَهَنَّمُ يَصۡلَوۡنَهَاۖ فَبِئۡسَ ٱلۡمَصِيرُ
Have you not seen how those who have been forbidden to hold secret conversations go back afterwards and hold them, and conspire with one another in what is sinful, hostile, and disobedient to the Messenger? When they come to you they greet you with words God has never used to greet you, and say inwardly, ‘Why does God not punish us for what we say?’ Hell will be punishment enough for them: they will burn there- an evil destination.
يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓاْ إِذَا تَنَٰجَيۡتُمۡ فَلَا تَتَنَٰجَوۡاْ بِٱلۡإِثۡمِ وَٱلۡعُدۡوَٰنِ وَمَعۡصِيَتِ ٱلرَّسُولِ وَتَنَٰجَوۡاْ بِٱلۡبِرِّ وَٱلتَّقۡوَىٰۖ وَٱتَّقُواْ ٱللَّهَ ٱلَّذِيٓ إِلَيۡهِ تُحۡشَرُونَ
You who believe, when you converse in secret, do not do so in a way that is sinful, hostile, and disobedient to the Messenger, but in a way that is good and mindful [of God]. Be mindful of God, to whom you will all be gathered.
إِنَّمَا ٱلنَّجۡوَىٰ مِنَ ٱلشَّيۡطَٰنِ لِيَحۡزُنَ ٱلَّذِينَ ءَامَنُواْ وَلَيۡسَ بِضَآرِّهِمۡ شَيۡـًٔا إِلَّا بِإِذۡنِ ٱللَّهِۚ وَعَلَى ٱللَّهِ فَلۡيَتَوَكَّلِ ٱلۡمُؤۡمِنُونَ
[Any other kind of] secret conversation is the work of Satan, designed to cause trouble to the believers, though it cannot harm them in the least unless God permits it. Let the believers put their trust in God.