Musannaf Ibn Abi Shayba 1:1846

Abu Bakr narrated to us, he said: Abu Usamah narrated to us, from Ubayd ibn Abi al-Wusaym, from Sulayman ibn Rashid, he said: Abu Rafi’, the freed slave of the Prophet, may Allah bless him and grant him peace, used to command me to hand him the urinal while he was on his bed, and he would urinate in it.