If I had not the fear of committing (sin) for concealing the knowledge I would not have written to him. Najda wrote to him saying (after praising the Almighty and invoking blessings on the Prophet): Tell me whether the Messenger of Allah ﷺ took women to participate with him in Jihad; (if he did), whether he allotted them a regular share from the booty; whether he killed the children of (the enemy in the war), how long an orphan would be entitled to consideration as such, and for whom the Khums (fifth part of the booty) was booty. Ibn Abbas wrote to him: You have written asking me whether the Messenger of Allah ﷺ took women with him to participate in Jihad. He did take them to the battle and sometimes he fought along with them. They would treat the wounded and were given a reward from the booty, but he did not assign any regular share for them. And the Messenger of Allah ﷺ did not kill the children of the enemy, so you should not kill the children. Also you have written to me asking me when the orphanhood of an orphan comes to an end. By my life, if a man has become bearded but is still incapable of getting his due from others or fulfilling his obligation towards them, (he is yet an orphan to be treated as such), but when he can look after his interests like grown-up people, he is no longer an orphan. And you have written to me inquiring about Khums as to whom it is meant for. (In this connection) we (the kinsmen of the Messenger of Allah) used to say: It is for us, but those people (i.e. Banu Umayya) have denied it to us. (Using translation from Muslim 1812a)
أَنْ أَكْتُمَ عِلْمِي لَمْ أَكْتُبْ إِلَيْهِ كَتَبَ إِلَيْهِ نَجْدَةُ أَمَّا بَعْدُ فَأَخْبِرْنِي هَلْ كَانَ رَسُولُ اللهِ ﷺ يَغْزُو بِالنِّسَاءِ مَعَهُ؟ وَهَلْ كَانَ يَضْرِبُ لَهُنَّ بِسَهْمٍ؟ وَهَلْ كَانَ يَقْتُلُ الصِّبْيَانَ؟ وَمَتَى يَنْقَضِي يُتْمُ الْيَتِيمِ؟ وَأَخْبِرْنِي عَنِ الْخُمُسِ لِمَنْ هُوَ؟ فَكَتَبَ إِلَيْهِ ابْنُ عَبَّاسٍ إِنَّ رَسُولَ اللهِ ﷺ قَدْ كَانَ يَغْزُو بِالنِّسَاءِ مَعَهُ فَيُدَاوِينَ الْمَرْضَى وَلَمْ يَكُنْ يَضْرِبُ لَهُنَّ بِسَهْمٍ وَلَكِنَّهُ كَانَ يُحْذِيهِنَّ مِنَ الغَنِيمَةِ وَإِنَّ رَسُولَ اللهِ ﷺ لَمْ يَكُنْ يَقْتُلُ الصِّبْيَانَ وَلا تَقْتُلِ الصِّبْيَانَ إِلا أَنْ تَكُونَ تَعْلَمُ مَا عَلِمَ الْخَضِرُ مِنَ الصَّبِيِّ الَّذِي قَتَلَهُ فَتَقْتُلَ الْكَافِرَ وَتَدَعَ الْمُؤْمِنَ وَكَتَبْتَ تَسْأَلُنِي عَنْ يُتْمِ الْيَتِيمِ مَتَى يَنْقَضِي؟ وَلَعَمْرِي إِنَّ الرَّجُلَ تَنْبُتُ لِحْيَتُهُ وَهُوَ ضَعِيفُ الْأَخْذِ لِنَفْسِهِ فَإِذَا كَانَ يَأْخُذُ لِنَفْسِهِ مِنْ صَالِحِ مَا يَأْخُذُ النَّاسُ فَقَدْ ذَهَبَ الْيُتْمُ وَأَمَّا الْخُمُسُ فَإِنَّا كُنَّا نُرَى أَنَّهُ لَنَا فَأَبَى ذَلِكَ عَلَيْنَا قَوْمُنَا