Surah Ali 'Imran 3:157

وَلَئِن قُتِلْتُمْ فِى سَبِيلِ ٱللَّهِ أَوْ مُتُّمْ لَمَغْفِرَةٌ مِّنَ ٱللَّهِ وَرَحْمَةٌ خَيْرٌ مِّمَّا يَجْمَعُونَ

And if you are killed in the cause of Allāh or die - then forgiveness from Allāh and mercy are better than whatever they accumulate [in this world].

Translation: Saheeh International

Tafsir

And if wa-la-in the lām is for oaths you are slain in God’s way in holy struggle or die read muttum or mittum from singular form māta yamūtu that is if death comes to you thereat forgiveness that is from God for your sins and mercy therefor from Him for you the clause introduced by the lām of la-maghfiratun …

Excerpt from Tafsir al-Jalalayn, commentary on 3:157, via Quran.com. The reader has the full commentary and 9 more tafsirs.