Usul al-Fiqh

Principles of Islamic jurisprudence (Arabic: أصول الفقه, romanized: ʾUṣūl al-Fiqh) are traditional methodological principles used in Islamic jurisprudence (fiqh) for deriving the rulings of Islamic law (sharia).
Traditional theory of Islamic jurisprudence elaborates how the scriptures (Quran and hadith) should be interpreted from the standpoint of linguistics and rhetoric. It also comprises methods for establishing authenticity of hadith and for determining when the legal force of a scriptural passage is abrogated by a passage revealed at a later date.