And from him, from Ahmad ibn Muhammad, from Ibn Abi Umayr, from Hammad, from al-Halabi, from Abu Abdillah عليه السلام, peace be upon him, who said: I (narrator) asked Imam عليه السلام about ‘the fasting person, May he clean his teeth with water?’ Imam عليه السلام said: “There is no harm, but he should not clean his teeth with the moist tooth-stick (siwak).”