Sahih Muslim
The Book of Jihad and Expedition (Kitab Al-Jihad wal-Siyar)
Book Number: 019 / Hadith Number: 4458
It has been narrated on the authority of Yazid b. Hurmuz who said: Najda b. 'Amir al-Haruri wrote to Ibn Abbas asking him about the slave and the woman as to whether they would get a share from the booty (it they participated in Jihad) ; about the killing of (enemy) children (in war) ; about the orphan as to when his orphanhood comes to an end; about kinsmen (of the Holy Prophet) as to who they are. He said to Yazid: Write to him. (If he were not likely to fall into folly, I would not have written to him.) Write: You have written asking about the woman and the slave whether they would get a share of the booty if they participated in Jihad. (You should know that) there is nothing of the sort for them except that they will be given a prize. And you have written asking me about the killing of the enemy children in war. (You should understand that) the Messenger of Allah (may peare be upon him) did not kill them. and thou shouldst not kill them unless thou knew what the companion of Moses (i. e. Khadir) knew about the boy he had killed. And you have written asking me about the orphan as to when the period of his orphanhood comes to an end, so that the sobriquet of" orphan" is dropped from him. (In this regard, you should know that) the sobriquet" orphan" will not be dropped from him until he attains maturity of body and mind. And you have written asking me about the close relatives (of the Holy Prophet) as to who they are. We think that it is we, but our people have denied us this (position and its concomitant privileges).