Yazid bin Hurmuz reported,

Najdah wrote to Ibn Abbas asking him about five matters. Ibn Abbas said, "Were it not that I would be concealing knowledge, I would not have written back to him."Najdah had written to him, "To proceed. Inform me, did the Messenger of Allah ﷺ take women out on military campaigns? Did he allot them a share of the spoils? Did he kill children? When does an orphan's orphanhood come to an end? And to whom does the fifth belong?"Ibn Abbas wrote back to him, "You wrote asking me whether the Messenger of Allah ﷺ took women out on military campaigns. He did indeed take them along, so they could tend to the wounded and be given gifts from the spoils, but he did not allot them a fixed share. As for the Messenger of Allah ﷺ, he did not kill children, so do not kill children.You wrote asking me when an orphan's orphanhood comes to an end. By my life, a man may have his beard grow in while he is still weak in handling his own affairs and weak in giving from his wealth. When he can manage his own affairs in the sound manner that people generally do, then his orphanhood has ended.You wrote asking me to whom the fifth belongs. We used to say it belongs to us, but our people refused us that claim."

عن يزيد بن هرمز

أن نجدة كتب إلى ابن عباس يسأله عن خمس خلال فقال ابن عباس: لولا أن أكتم علما ما كتبت إليه، كتب إليه نجدة: أما بعد فأخبرني هل كان رسول الله ﷺ يغزو بالنساء؟ وهل كان يضرب لهن بسهم؟ وهل كان يقتل الصبيان؟ ومتى ينقضي يتم اليتيم؟ وعن الخمس لمن هو؟ فكتب إليه ابن عباس: كتبت تسألني هل كان رسول الله ﷺ يغزو بالنساء، وقد كان يغزو بهن، فيداوين الجرحى، ويحذين من الغنيمة وأما بسهم فلم يضرب لهن، وإن رسول الله ﷺ لم يكن يقتل الصبيان، فلا تقتل الصبيان. وكتبت تسألني متى ينقضي يتم اليتيم؟ فلعمري إن الرجل لتنبت لحيته وإنه لضعيف الأخذ لنفسه، ضعيف العطاء منها، فإذا أخذ لنفسه من صالح ما يأخذ الناس فقد ذهب عنه اليتم. وكتبت تسألني عن الخمس لمن هو؟ وإنا كنا نقول: هو لنا فأبى علينا قومنا ذاك.