Al-Baqarah 2:154

Wala taqooloo liman yuqtalu feesabeeli Allahi amwatun bal ahyaon walakinla tashAAuroon

And do not say about those who are killed in the way of Allāh, "They are dead." Rather, they are alive, but you perceive [it] not.

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.