Musnad Ahmad Hadith 2791

Najdah wrote to Ibn ‘Abbas (رضي الله عنه), asking him about five things. Ibn 'Abbas said: People are saying that Ibn 'Abbas is corresponding with the Harooriyyah (i.e. the Khawarij). Were it not for (fear of) concealing knowledge, I would not have written to him. Najdah wrote to him (saying): Tell me, did the Messenger of Allah (ﷺ) take women on campaigns with him? Did he give them a share (of the booty)? Did he kill children? At what point is an orphan no longer considered to be such? And about the khumus - who is it for? Ibn 'Abbas wrote to him saying. The Messenger of Allah (ﷺ) did take women on campaigns with him so that they might treat the wounded, and they were not given any share, but they were given something from the booty. The Messenger of Allah (ﷺ) did not kill children, so do not kill children, unless you have knowledge such as al-Khadir had about the boy whom he killed, so you kill the kafir and leave the believer. And you wrote and asked me when the orphan is no longer considered to be such. Indeed, a man's beard may grow but he may still be incapable of getting his due from others, but when he can look after his affairs like other people, then he is no longer regarded as an orphan. And with regard to the khumus and who it is for, we used to think that it was for us, but our people have denied it to us.