The Messenger of Allah ﷺ said, "Were it not that I would cause hardship," and Muhammad said, "Were it not that it would cause hardship upon my community, I would delay the Isha prayer until a third of the night had passed, and I would command them to use the siwak at every prayer."
حدثنا يعلى ومحمد ابنا عبيد قالا حدثنا محمد بن إسحاق عن محمد بن إبراهيم عن أبي سلمة بن عبد الرحمن
قال رسول الله ﷺ لولا أن أشق وقال محمد لولا أن يشق على أمتي لأخرت صلاة العشاء إلى ثلث الليل ولأمرتهم بالسواك عند كل صلاة
Its isnad is sahih. Its narrators are famous and trustworthy, and Ibn Ishaq explicitly stated that he heard it directly, as recorded by Tirmidhi and others. Muhammad bin Ibrahim is Ibn Harith Taymi, the trustworthy and firmly reliable narrator. The hadith has already appeared at 10566.