Musannaf Ibn Abi Shayba 1:1807

Waki’ narrated to us, from al-Mundhir ibn Tha’labah al-‘Abdi, from ‘Abdullah ibn Buraydah al-Aslami, who said: When the Prophet, peace and blessings of Allah be upon him, would wake up from his family, he would call for a slave girl who was called Barirah for the siwak.