Kathir bin 'Ubaid al-Taymi

"The Prophet (ﷺ) of Allah (ﷺ) would clean his teeth with the Siwak, then he would give me the Siwak in order to wash it. So I would first use it myself, then wash it and return it.

The Messenger of Allah (ﷺ) used to have himself cupped on the top of his head and between his shoulders, and that he used to say: If anyone pours out any of his blood, he will not suffer if he applies

The Prophet (ﷺ) said: When one has a look into the house, then there is no (need of) permission.