Verse 13

ذَٰلِكَ بِأَنَّهُمْ شَآقُّوا۟ ٱللَّهَ وَرَسُولَهُۥ وَمَن يُشَاقِقِ ٱللَّهَ وَرَسُولَهُۥ فَإِنَّ ٱللَّهَ شَدِيدُ ٱلْعِقَابِ

This is because they indeed opposed God and His messenger. And whoever opposes God and His messenger shall expect that indeed God exacts the severest consequence.