Surah Az-Zumar 39:54

وَأَنِيبُوٓا۟ إِلَىٰ رَبِّكُمْ وَأَسْلِمُوا۟ لَهُۥ مِن قَبْلِ أَن يَأْتِيَكُمُ ٱلْعَذَابُ ثُمَّ لَا تُنصَرُونَ

And return [in repentance] to your Lord and submit to Him before the punishment comes upon you; then you will not be helped.

Translation: Saheeh International

Tafsir

And turn return penitently to your Lord and submit perform deeds sincerely to Him before the chastisement comes on you whereupon you will not be helped to ward it off if you have not repented.

Excerpt from Tafsir al-Jalalayn, commentary on 39:54, via Quran.com. The reader has the full commentary and 9 more tafsirs.