يٰٓاَيُّهَا الَّذِيْنَ اٰمَنُوْا لَا تَكُوْنُوْا كَالَّذِيْنَ كَفَرُوْا وَقَالُوْا لِاِخْوَانِهِمْ اِذَا ضَرَبُوْا فِى الْاَرْضِ اَوْ كَانُوْا غُزًّى لَّوْ كَانُوْا عِنْدَنَا مَا مَاتُوْا وَمَا قُتِلُوْاۚ لِيَجْعَلَ اللّٰهُ ذٰلِكَ حَسْرَةً فِيْ قُلُوْبِهِمْ ۗ وَاللّٰهُ يُحْيٖ وَيُمِيْتُ ۗ وَاللّٰهُ بِمَا تَعْمَلُوْنَ بَصِيْرٌ ( آل عمران: ١٥٦ )
Yaaa ayyuhul lazeena aamanoo laa takoonoo kallazeena kafaroo wa qaaloo li ikhwaanihim izaa daraboo fil ardi aw kaanoo ghuzzal law kaanoo 'indanaa maa maatoo wa maa qutiloo liyaj'alal laahu zaalika hasratan fee quloobihim; qallaahu yuhyee wa yumeet; wallaahu bimaa ta'maloona Baseer (ʾĀl ʿImrān 3:156)
Sahih International:
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. (Ali 'Imran [3] : 156)
1 Mufti Taqi Usmani
O you who believe, do not be like those who disbelieved and said about their brethren while they travelled on the earth or had to fight, “Had they been with us, they would have not died, nor would they have been killed.” The result is that Allah makes it a remorse resting in their hearts. Allah gives life and brings death; Allah is watchful of what you do.