"Were it not that it would be too difficult for my Ummah, I would have commanded them to use the Siwak at (the time of) every Salah."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لَوْلاَ أَنْ أَشُقَّ عَلَى أُمَّتِي لأَمَرْتُهُمْ بِالسِّوَاكِ عِنْدَ كُلِّ صَلاَةٍ