Sunan Ibn Majah, Book 1, Hadith 305 (In-Book)

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.'"

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا شَرِيكٌ، عَنِ الْمِقْدَامِ بْنِ شُرَيْحِ بْنِ هَانِئٍ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، قَالَ قُلْتُ أَخْبِرِينِي بِأَىِّ، شَىْءٍ كَانَ النَّبِيُّ ـ صلى الله عليه وسلم ـ يَبْدَأُ إِذَا دَخَلَ عَلَيْكِ قَالَتْ كَانَ إِذَا دَخَلَ يَبْدَأُ بِالسِّوَاكِ ‏.‏

sunnah.com