Sayyidah Aishah Siddiqah (may Allah be pleased with her) reports this saying of the Prophet (peace and blessings be upon him): "Praying two rak'ahs with the miswak is more excellent than seventy rak'ahs without the miswak."
Al-Bazzar recorded it, and its narrators have been declared trustworthy.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2555