Sayyidah Umm Salamah (may Allah be pleased with her) narrates that the Prophet (peace and blessings be upon him) said: "Jibril kept urging me to use the miswak until I feared for my molars."
Al-Tabarani recorded it in al-Mu'jam al-Kabir; its narrators have been declared trustworthy, though there is disagreement about some of them.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2563