It is narrated from the Mother of the Believers, Sayyidah Aishah (may Allah be pleased with her), that she said: "The Messenger of Allah (peace and blessings be upon him) passed away between my chest and my throat (in my lap), and I had him leaning against my chest. Meanwhile Sayyiduna Abd al-Rahman bin Abi Bakr (may Allah be pleased with him) came, and he had a tooth-stick (siwak) with him. The Prophet (peace and blessings be upon him) called him and took that siwak from him. He (peace and blessings be upon him) wanted to clean his teeth but was unable (due to weakness), so I took the siwak from him, softened it (by chewing), then gave it to him. He (peace and blessings be upon him) began cleaning his teeth with it, then his hand became heavy, and I heard him say: 'Fi al-rafiq al-a'la' ((O Allah,) in the company of the Highest Companion). Then his soul was taken, and I did not realise it (immediately)."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Hisham bin Urwah (may Allah have mercy on him) except Ma'mar (may Allah have mercy on him), and Rabah bin Zayd (may Allah have mercy on him) is alone in narrating it from him."