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.
How is one to wade through the apparent welter of irreconcilable primary Islamic sources? What is one to do when faced with opposing practices of the Prophet (Sallallahu Alayhi Wa Sallam) on the same issue? When is a practice deemed necessary or recommended? These are some of the topics discussed in usul al-fiqh.