The Messenger of Allah ﷺ said, "I have repeatedly urged you concerning the use of the siwak."
حدثنا عفان حدثنا عبد الوارث حدثنا شعيب بن الحبحاب
قال رسول الله ﷺ قد أكثرت عليكم في السواك
No references are available.
Its isnad is sahih, mentioned previously at 12398.