The Messenger of Allah ﷺ said, "Were it not that I would place a hardship upon my community, I would have commanded them to use the tooth-stick before every prayer."Zayd bin Khalid used to keep the tooth-stick tucked behind his ear in the same way a scribe keeps his pen, and whenever he stood up to pray, he would use it to clean his teeth.
قال رسول الله ﷺ: لولا أن أشق على أمتي لأمرتهم بالسواك عند كل صلاة. قال: فكان زيد بن خالد يضع السواك منه موضع القلم من أذن الكاتب، كلما قام إلى الصلاة استاك.
Imam Ahmad (17048) narrated it, saying, Abdul-Samad (that is, Ibn Abdul-Warith) told us, he said, Harb, meaning Ibn Shaddad, told us, from Yahya (that is, Ibn Abu Kathir), Abu Salama told us. And Muhammad bin Fudayl told us, from Muhammad bin Ishaq, from Muhammad bin Ibrahim, from Abu Salama, from... And Zayd bin Khalid Juhani told us, and he mentioned it.The first chain is sahih. As for the second chain, it contains Muhammad bin Ishaq, who was a mudallis and he narrated with an ambiguous form of transmission (an'ana).With the second chain, Abu Dawud (47), Tirmidhi (23), and Nasai in al-Kubra (3029) narrated it, all of them from the hadith of Muhammad bin Ishaq, from Muhammad bin Ibrahim Taymi, in the same manner. Tirmidhi added, from the part attributed to the Prophet, "And I would have delayed the night prayer until a third of the night."Tirmidhi said, "This is a hasan sahih hadith."