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 along on military campaigns? Did he assign them a share of the spoils? Did he kill children? When does the orphanhood of an orphan come to an end? And to whom does the one-fifth belong?"Ibn Abbas wrote back to him, "You wrote asking me whether the Messenger of Allah ﷺ used to take women on campaigns. He did indeed take them along, and they would tend to the wounded and be given gifts from the spoils. As for a fixed share, he did not assign them one. The Messenger of Allah ﷺ did not kill children, so do not kill children.You wrote asking me when the orphanhood of an orphan ends. By my life, a man's beard may grow in while he is still weak in providing for himself and weak in giving from his own resources. But once he takes for himself in the sound manner that people generally do, his orphanhood has departed from him.You wrote asking me about the one-fifth, to whom does it belong? We used to say it belongs to us, but our people refused us that."

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 ينقضى 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 ينقضى يتم اليتيم؟ فلعمرى! 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.