Surah Al-Anfal 8:13

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

That is because they opposed Allāh and His Messenger. And whoever opposes Allāh and His Messenger - indeed, Allāh is severe in penalty.

Translation: Saheeh International

Tafsir

That chastisement befalling them is because they had contended with they had opposed God and His Messenger whoever contends with God and with His Messenger surely God is severe in retribution against him.

Excerpt from Tafsir al-Jalalayn, commentary on 8:13, via Quran.com. The reader has the full commentary and 9 more tafsirs.