وَلَا تَقُوْلُوْا لِمَنْ يُّقْتَلُ فِيْ سَبِيْلِ اللّٰهِ اَمْوَاتٌ ۗ بَلْ اَحْيَاۤءٌ وَّلٰكِنْ لَّا تَشْعُرُوْنَ ( البقرة: ١٥٤ )
Wa laa taqooloo limai yuqtalu fee sabeelil laahi amwaat; bal ahyaaa'unw wa laakil laa tash'uroon (al-Baq̈arah 2:154)
And do not say about those who are killed in the way of Allah, "They are dead." Rather, they are alive, but you perceive [it] not. (Al-Baqarah  : 154)
1 Mufti Taqi Usmani
Do not say of those who are slain in the way of Allah that they are dead. Instead, they are alive, but you do not perceive.