﴿مِنَ الْمُؤْمِنِينَ رِجَالٌ صَدَقُوا مَا عَاهَدُوا الله عَلَيْهِ﴾ [Among the believers are men who have been true to what they promised Allah], meaning when they pledged to Him that they would not flee, and they were true in their meeting with the enemy; and that was on the day of Uhud. ﴿فَمِنْهُمْ مَنْ قَضَى نحبه﴾ [So among them is he who has fulfilled his vow], meaning: his appointed term, according to the interpretation of some of them, ﴿وَمِنْهُم من ينْتَظر﴾ [and among them is he who awaits] his appointed term, ﴿وَمَا بدلُوا تبديلا﴾ [and they did not change (their commitment) by any alteration], as the hypocrites had changed.
Muhammad said: The root of al-nahb is the vow (al-nadhr); as if a people had made vows that if they encountered the enemy, they would fight until they were killed or Allah granted them victory, so they were killed, and it was said: So-and-so has fulfilled his vow; when he is killed.
﴿مِنَ الْمُؤْمِنِينَ رِجَالٌ صَدَقُوا مَا عَاهَدُوا الله عَلَيْهِ﴾ حِينَ بَايَعُوهُ عَلَى أَلَّا يَفِرُّوا وَصَدَقُوا فِي لِقَائِهِمُ الْعَدُوَّ؛ وَذَلِكَ يَوْمَ أُحُدٍ. ﴿فَمِنْهُمْ مَنْ قَضَى نحبه﴾ يَعْنِي: أَجَلَهُ؛ فِي تَفْسِيرِ بَعْضِهِمْ ﴿وَمِنْهُم من ينْتَظر﴾ أَجله ﴿وَمَا بدلُوا تبديلا﴾ كَمَا بَدَّلَ الْمُنَافِقُونَ.
قَالَ مُحَمَّدٌ: أَصْلُ النَّحْبِ: النَّذْرِ؛ كَأَنَّ قَوْمًا نذورا إِنْ لَقُوا الْعَدُوَ أَنْ يُقَاتِلُوا؛ حَتَّى يُقْتَلُوا أَوْ يَفْتَحِ اللَّهُ، فَقُتِلُوا فَقِيلَ: فُلَانٌ قَضَى نَحْبَهُ؛ إِذا قتل.