Musannaf Ibn Abi Shayba 28:1124

'Abd al-Rahim ibn Sulayman narrated to us, from Muhammad ibn Ishaq, from al-Zuhri and Muhammad ibn 'Ali, from Yazid ibn Hurmuz, who said: Najdah wrote to Ibn 'Abbas asking him about women: Did they used to attend war with the Messenger of Allah, may Allah bless him and grant him peace? And was a share (of the spoils) allotted to them? Yazid said: I wrote the letter of Ibn 'Abbas to Najdah: They did used to attend with the Messenger of Allah, may Allah bless him and grant him peace. As for a share being allotted to them, no; but he used to give them a gift (radkh).