It was narrated from Miqdam bin Shuraih bin Hani' that his father said:
"I said to 'Aishah: 'Tell me, what was the first thing that the Messenger of Allah did when he entered upon you?' She said: 'The first thing he would do would be to use the tooth stick.'" (RU)
English reference (RU): Vol. 1, Book 1, Hadith 290 (RU)
Arabic reference (RU): Book 1, Hadith 305 (RU)