ثُمَّأَنزَلَعَلَيْكُممِّنۢبَعْدِٱلْغَمِّأَمَنَةًۭنُّعَاسًۭايَغْشَىٰطَآئِفَةًۭمِّنكُمْ ۖوَطَآئِفَةٌۭقَدْأَهَمَّتْهُمْأَنفُسُهُمْيَظُنُّونَبِٱللَّهِغَيْرَٱلْحَقِّظَنَّٱلْجَـٰهِلِيَّةِ ۖيَقُولُونَهَللَّنَامِنَٱلْأَمْرِمِنشَىْءٍۢ ۗقُلْإِنَّٱلْأَمْرَكُلَّهُۥلِلَّهِ ۗيُخْفُونَفِىٓأَنفُسِهِممَّالَايُبْدُونَلَكَ ۖيَقُولُونَلَوْكَانَلَنَامِنَٱلْأَمْرِشَىْءٌۭمَّاقُتِلْنَاهَـٰهُنَا ۗقُللَّوْكُنتُمْفِىبُيُوتِكُمْلَبَرَزَٱلَّذِينَكُتِبَعَلَيْهِمُٱلْقَتْلُإِلَىٰمَضَاجِعِهِمْ ۖوَلِيَبْتَلِىَٱللَّهُمَافِىصُدُورِكُمْوَلِيُمَحِّصَمَافِىقُلُوبِكُمْ ۗوَٱللَّهُعَلِيمٌۢبِذَاتِٱلصُّدُورِ١٥٤

Then after distress, He sent down upon you security [in the form of] drowsiness, overcoming a faction of you, while another faction worried about themselves, thinking of Allāh other than the truth - the thought of ignorance, saying, "Is there anything for us [to have done] in this matter?" Say, "Indeed, the matter belongs completely to Allāh." They conceal within themselves what they will not reveal to you. They say, "If there was anything we could have done in the matter, we [i.e., some of us] would not have been killed right here." Say, "Even if you had been inside your houses, those decreed to be killed would have come out to their death beds." [It was] so that Allāh might test what is in your breasts and purify what is in your hearts. And Allāh is Knowing of that within the breasts.

Indeed, those of you who turned back on the day the two armies met [at Uḥud] - it was Satan who caused them to slip because of some [blame] they had earned. But Allāh has already forgiven them. Indeed, Allāh is Forgiving and Forbearing.

O you who have believed, do not be like those who disbelieved and said about their brothers when they traveled through the land or went out to fight, "If they had been with us, they would not have died or have been killed," so Allāh makes that [misconception] a regret within their hearts. And it is Allāh who gives life and causes death, and Allāh is Seeing of what you do.

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].