Musnad Ahmad 25:1440

Yazid narrated to us, he said: Muhammad—meaning Ibn Ishaq—informed us, from Muhammad ibn Ali and from al-Zuhri, from Yazid ibn Hurmuz, who said: Najdah al-Haruri wrote to Ibn Abbas asking him about the killing of children, and whether women used to attend war with the Prophet, may Allah bless him and grant him peace, and whether a share [of the spoils] was allotted to them. Yazid ibn Hurmuz said: And I wrote Ibn Abbas’s letter to Najdah. He wrote to him: You wrote asking me about the killing of children, and you say: "The scholar, the companion of Musa, killed the boy." If you knew about children what that scholar knew, you would kill them, but you do not know, so avoid them, "for the Messenger of Allah, may Allah bless him and grant him peace, has forbidden their killing." And you wrote asking me about women, whether they used to attend war with the Prophet, may Allah bless him and grant him peace, and whether a share was allotted to them. "They did indeed attend with the Prophet, may Allah bless him and grant him peace, but as for a share being allotted to them, he did not do that, though he would give them a gift (radkh)."