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 Allah makes that ˹misconception˺ a regret within their hearts. And it is Allah who gives life and causes death, and Allah is Seeing of what you do.  

يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تَكُونُوا كَالَّذِينَ كَفَرُوا وَقَالُوا لِإِخْوَانِهِمْ إِذَا ضَرَبُوا فِي الْأَرْضِ أَوْ كَانُوا غُزًّى لَوْ كَانُوا عِنْدَنَا مَا مَاتُوا وَمَا قُتِلُوا لِيَجْعَلَ اللَّهُ ذَٰلِكَ حَسْرَةً فِي قُلُوبِهِمْ ۗ وَاللَّهُ يُحْيِي وَيُمِيتُ ۗ وَاللَّهُ بِمَا تَعْمَلُونَ بَصِيرٌ  

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

وَلَئِنْ قُتِلْتُمْ فِي سَبِيلِ اللَّهِ أَوْ مُتُّمْ لَمَغْفِرَةٌ مِنَ اللَّهِ وَرَحْمَةٌ خَيْرٌ مِمَّا يَجْمَعُونَ  

And whether you die or are killed, unto Allah you will be gathered.  

وَلَئِنْ مُتُّمْ أَوْ قُتِلْتُمْ لَإِلَى اللَّهِ تُحْشَرُونَ