(Ahsaab) 33 : 23
مِنَ الْمُؤْمِنِينَ رِجَالٌ صَدَقُوا مَا عَاهَدُوا اللَّهَ عَلَيْهِ ۖ فَمِنْهُمْ مَنْ قَضَىٰ نَحْبَهُ وَمِنْهُمْ مَنْ يَنْتَظِرُ ۖ وَمَا بَدَّلُوا تَبْدِيلًا
Among the believers some testified the covenant made with Allah, and there are some who fulfilled the aim of life through martyrdom, and some are waiting for it, they have not changed it.
See explanation 3: 69-172; 8: 39; 9: 111-112.