Surah Al-Hijr 15:2

رُّبَمَا يَوَدُّ ٱلَّذِينَ كَفَرُوا۟ لَوْ كَانُوا۟ مُسْلِمِينَ

Perhaps those who disbelieve will wish that they had been Muslims.

Translation: Saheeh International

Tafsir

It may be that read rubbamā or rubamā those who disbelieve on the Day of Resurrection when they witness their predicament and that of the Muslims will wish that they had been muslims rubba here is used to indicate ‘many’ since many of them will wish this; …

Excerpt from Tafsir al-Jalalayn, commentary on 15:2, via Quran.com. The reader has the full commentary and 9 more tafsirs.