Surah Al-Anbya 21:39

لَوْ يَعْلَمُ ٱلَّذِينَ كَفَرُوا۟ حِينَ لَا يَكُفُّونَ عَن وُجُوهِهِمُ ٱلنَّارَ وَلَا عَن ظُهُورِهِمْ وَلَا هُمْ يُنصَرُونَ

If those who disbelieved but knew the time when they will not avert the Fire from their faces or from their backs and they will not be aided...

Translation: Saheeh International

Tafsir

God exalted be He says If those who disbelieved only knew of the time when they shall not be able to ward off repel the Fire from their faces nor from their backs nor shall they be helped nor shall they be protected from it at the Resurrection the response to the conditional particle law ‘if only’ is something along …

Excerpt from Tafsir al-Jalalayn, commentary on 21:39, via Quran.com. The reader has the full commentary and 9 more tafsirs.