The Messenger of Allah ﷺ said, "Were it not that I would burden my community, I would have commanded them to use the siwak before every prayer."
حدثنا أبو كريب حدثنا عبدة بن سليمان عن محمد بن عمرو عن أبي سلمة
قال رسول الله ﷺ لولا أن أشق على أمتي لأمرتهم بالسواك عند كل صلاة
Sourcing, sahih.Ahmad also recorded it (3/399) from Abda with the same wording, and its chain is hasan.Bukhari (887) and Muslim (252) also recorded it from the hadith of Abu Hurairah with a similar meaning.This is a mutawatir hadith, as mentioned in Azhar Mutanathira by Suyuti (no. 20), Laqt (no. 67), and Nazm Mutanathir (no. 26).The hadith of Muhammad bin Ishaq will come at no. 23.On this subject, it is also reported from Abu Bakr Siddiq [Ahmad 1/3, 10], Ali [Ahmad 1/120 and Tabarani in Awsat 2/138, no. 1260], Ayesha [Ibn Hibban (Ihsan) 2/1066 and Bazzar (Kashf Astar) 12/241, no. 493], Ibn Abbas [Tabarani in Kabir 11/85, no. 11125, and 11/87, no. 11133], Huzaifa (I did not find it with this wording, and Suyuti attributed it to Daylami, and it has another wording that is agreed upon), Zayd bin Khalid [will come at no. 23], Anas [Abu Naeem in Siwak, as Suyuti said], Abdullah bin Amr [Abu Naeem in Siwak, as Suyuti said], Umm Habiba [Ahmad 6/325], Ibn Umar [Tabarani in Kabir 12/375, no. 13389, and 12/435, no. 13592, and Ahmad 2/108], Abu Umama [mentioned by Daylami, as Suyuti said, and it has another wording with Ahmad 6/325], Abu Ayub [mentioned by Daylami, and it has another wording with Tirmidhi in the chapter on marriage], Tammam bin Abbas [Ahmad 1/224], Abdullah bin Hanzala [Ibn Manda mentioned it, as Suyuti said, and it has another wording with Abu Dawud, no. 48], Umm Salama [mentioned by Daylami, see Talkhis Habir 1/67 and Targhib 1/131], Wathila bin Asqa [mentioned by Daylami, and it has another wording with Ahmad 3/490], and Abu Musa [mentioned by Daylami, and it has another wording that is agreed upon].