Musannaf Ibn Abi Shayba 28:1122

Narrated to us Abd al-Rahim ibn Sulayman, from Hisham ibn Hassan, from Hafsa bint Sirin, from Umm Atiyya al-Ansariyya, who said: I went on seven expeditions with the Messenger of Allah (may Allah bless him and grant him peace). I would stay behind in their camps, prepare food for them, treat the wounded for them, and attend to the sick.