The Qur'an and Sunnah are the two primary sources of Muslim faith, life, law and morality. The Qur'an is for Muslims the foundation of their faith and the Sunnah is the framework of their morality. Together they constitute the two sources of the law (Shari ah) of God, a guide to prosperity and happiness in this life and to the bliss of the hereafter.
The Sacred Law's sources are four: the Qur'an, the Sunnah, consensus, and analogy. Certainly, the Qur'an is the most authoritative. In fact, Zarkashi related from al-Qaffal al-Shashi that the Sacred Law is based on just one: the Qur'an