Chapter: Siwak (to clean the teeth with Siwak which is a tooth-brush in the form of a pencil from the roots of the Arak tree

My father said, "I came to the Prophet (ﷺ) and saw him carrying a Siwak in his hand and cleansing his teeth, saying, 'U' U'," as if he was retching while the Siwak was in his mouth."

Whenever the Prophet (ﷺ) got up at night, he used to clean his mouth with Siwak.