Sahih Muslim , Book 2, Hadith 488 (USC-MSA) ⓘ
Miqdam b. Shuraih narrated it from his father who said: I asked A'isha what Allah's Apostle did first when he entered his house, and she replied: He used tooth-stick (first of all).
حَدَّثَنَا أَبُو كُرَيْبٍ، مُحَمَّدُ بْنُ الْعَلاَءِ حَدَّثَنَا ابْنُ بِشْرٍ، عَنْ مِسْعَرٍ، عَنِ الْمِقْدَامِ بْنِ شُرَيْحٍ، عَنْ أَبِيهِ، قَالَ سَأَلْتُ عَائِشَةَ قُلْتُ بِأَىِّ شَىْءٍ كَانَ يَبْدَأُ النَّبِيُّ صلى الله عليه وسلم إِذَا دَخَلَ بَيْتَهُ قَالَتْ بِالسِّوَاكِ .
also referenced under: Book 2, Hadith 57 (In-Book) & Hadith 253 (Reference)