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.'" (ES)
English reference (ES): Vol. 1, Book 1, Hadith 287 (ES)
Arabic reference (ES): Book 1, Hadith 302 (ES)