Muwatta Malik, Book 18, Hadith 60 (USC-MSA) ⓘ

Yahya related to me from Malik that he had heard that the people of knowledge did not disapprove of people fasting using tooth-sticks at any hour of the day in Ramadan, whether at the beginning or the end, nor had he heard any of the people of knowledge disapproving of or forbidding the practice. Yahya said that he heard Malik say, about fasting for six days after breaking the fast at the end of Ramadan, that he had never seen any of the people of knowledge and fiqh fasting them. He said, "I have not heard that any of our predecessors used to do that, and the people of knowledge disapprove of it and they are afraid that it might become a bida and that common and ignorant people might join to Ramadan what does not belong to it, if they were to think that the people of knowledge had given permission for that to be done and were seen doing it. Yahya said that he heard Malik say, "I have never heard any of the people of knowledge and fiqh and those whom people take as an example forbidding fasting on the day of jumua. Fasting on it is good, and I have seen one of the people of knowledge fasting it, and it seemed to me that he was keen to do so."