I heard the Messenger of Allah ﷺ say, "Were it not that I would impose hardship on my community, I would have commanded them to use the tooth-stick before every prayer, and I would have delayed the night prayer until a third of the night had passed."
سمعت رسول الله ﷺ يقول: لولا أن أشق على أمتي لأمرتهم بالسواك عند كل صلاة، ولأخرت صلاة العشاء إلى ثلث الليل.
Tirmidhi reported it (23), saying, Hannad told us, Abdah bin Sulayman told us, from Muhammad bin Ishaq, from Muhammad bin Ibrahim, from Abu Salama, from Zayd bin Khalid Juhani, and he related the hadith. Tirmidhi said, "hasan sahih." I say, it contains Muhammad bin Ishaq, who is a mudallis and he narrated using "an" (indicating possible concealment of the source). Abu Dawud (47) and Nasai in Kubra (3/291) also reported it through his route, except that neither of them mentioned "delaying the Isha prayer." Its citation was given earlier in the book of Purification, in the chapter on what has been said about the tooth-stick.The hadith has another chain, reported by Imam Ahmad (17048), who said, Abdul-Samad told us, saying, Harb, meaning Ibn Shaddad, told us, from Yahya, Abu Salama told us, from Zayd bin Khalid Juhani, and he related the hadith about the tooth-stick without mentioning the delay of the Isha prayer. This chain is sahih, and Yahya here is Ibn Abu Kathir.