Messenger of Allah ﷺ said, "If I had not found it hard for my followers or the people, I would have ordered them to clean their teeth with Siwak for every prayer."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لَوْلاَ أَنْ أَشُقَّ عَلَى أُمَّتِي أَوْ عَلَى النَّاسِ لأَمَرْتُهُمْ بِالسِّوَاكِ مَعَ كُلِّ صَلاَةٍ