Nu’aym ibn Mas’ud reported: I heard the Messenger of Allah, peace and blessings be upon him, speaking to those who were reading the letter of the false prophet Musaylimah the Liar, saying, “What do you both say?” They said, “We say what he said.” The Prophet said, “By Allah, were it not that diplomats are not killed, I would strike both of your necks.”
Source: Sunan Abī Dāwūd 2761
Grade: Sahih (authentic) according to Al-Albani
Ibn Qudamah said, “When immunity is given to enemy combatants, it is forbidden to kill them, seize their wealth, or confront them. Immunity is valid if given by any adult, sane, selected Muslim, male or female, free or slave. This was said by Al-Thawri, Al-Awza’i, Al-Shafi’i, Ishaq, Ibn al-Qasim, and the majority of the people of knowledge.”
Source: al-Mughnī 9/195
عَنْ نُعَيْمٍ بن مسعود قَالَ سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ لَهُمَا حِينَ قَرَأَ كِتَابَ مُسَيْلِمَةَ مَا تَقُولَانِ أَنْتُمَا قَالَا نَقُولُ كَمَا قَالَ قَالَ أَمَا وَاللَّهِ لَوْلَا أَنَّ الرُّسُلَ لَا تُقْتَلُ لَضَرَبْتُ أَعْنَاقَكُمَا
2761 سنن أبي داود كتاب الجهاد باب في الرسل
2761 المحدث الألباني خلاصة حكم المحدث صحيح في صحيح أبي داود
قال ابن قدامة أَنَّ الْأَمَانَ إذَا أُعْطِيَ أَهْلَ الْحَرْبِ حَرُمَ قَتْلُهُمْ وَمَالُهُمْ وَالتَّعَرُّضُ لَهُمْ وَيَصِحُّ مِنْ كُلِّ مُسْلِمٍ بَالِغٍ عَاقِلٍ مُخْتَارٍ ذَكَرًا كَانَ أَوْ أُنْثَى حُرًّا كَانَ أَوْ عَبْدًا وَبِهَذَا قَالَ الثَّوْرِيُّ وَالْأَوْزَاعِيُّ وَالشَّافِعِيُّ وَإِسْحَاقُ وَابْنُ الْقَاسِمِ وَأَكْثَرُ أَهْلِ الْعِلْمِ
9/195 المغني لابن قدامة كتاب الجهاد