VERILY, this Qur'an shows the way to all that is most uprightand gives the believers who do good deeds the glad tiding that theirs will be a great reward;
Al-Isra (The Journey by Night) Verse 9
Allah's Apostle 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."
Sahih Bukhari: Volume 2, Book 13, Number 12