Shurayh reported: I asked Aisha, saying, “What was the first thing the Prophet, peace and blessings be upon him, did when he entered his house?” Aisha said, “Use the toothstick.”
Source: Ṣaḥīḥ Muslim 253
Grade: Sahih (authentic) according to Muslim
عَنْ شُرَيْحٍ سَأَلْتُ عَائِشَةَ قُلْتُ بِأَيِّ شَيْءٍ كَانَ يَبْدَأُ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا دَخَلَ بَيْتَهُ قَالَتْ بِالسِّوَاكِ
253 صحيح مسلم كتاب الطهارة باب السواك