It is narrated from the Mother of the Believers, Sayyidah Aishah (may Allah be pleased with her), that the Prophet (peace and blessings be upon him) said: "Among the best habits of the fasting person is the siwak (tooth-stick)."
Imam al-Tabarani (may Allah have mercy on him) said: "Only Mujalid and al-Sari bin Isma'il narrated this hadith from al-Sha'bi; Abu Isma'il al-Mu'addib is alone in narrating it from Mujalid, and Abbad is alone in narrating it from al-Sari."
Hadith Referenceالمعجم الأوسط / باب الميم / 8420
Hadith Takhrij«أخرجه ابن ماجه فى «سننه» برقم: 1677، والبيهقي فى «السنن الكبرى» برقم: 8416، والدارقطني فى «سننه» برقم: 2371، وابن أبي شيبة فى «مصنفه» برقم: 9244، والطبراني فى «الأوسط» برقم: 8526»