It was narrated that Abu Hurairah said:
"The Messenger of Allah said: 'Were it not that it would be too difficult for my Ummah (nation), I would have commanded them to use the tooth stick at every time of prayer.'" (DE)
English reference (DE): Vol. 1, Book 1, Hadith 287 (DE)
Arabic reference (DE): Book 1, Hadith 302 (DE)