Sahih Bukhari | Volume 5 | Hadith Number 730

Narrated by 'Aisha
It was one of the favours of Allah towards me that Allah's Apostle expired in my house on the day of my turn while he was leaning against my chest and Allah made my saliva mix with his saliva at his death. 'Abdur-Rahman entered upon me with a Siwak in his hand and I was supporting (the back of) Allah's Apostle (against my chest). I saw the Prophet looking at it (i.e. Siwak) and I knew that he loved the Siwak, so I said (to him), "Shall I take it for you ? " He nodded in agreement. So I took it and it was too stiff for him to use, so I said, "Shall I soften it for you ?" He nodded his approval. So I softened it and he cleaned his teeth with it. In front of him there was a jug or a tin, (The sub-narrator, 'Umar is in doubt as to which was right) containing water. He started dipping his hand in the water and rubbing his face with it, he said, "None has the right to be worshipped except Allah. Death has its agonies." He then lifted his hands (towards the sky) and started saying, "With the highest companion," till he expired and his hand dropped down.