Al-Qadi Abu Ya'la
Abū Yaʿlā Muḥammad Ibn al-Ḥusayn Ibn al-Farrāʾ
|Born||380 A.H / 990 C.E.|
|Died||458 A.H / 1066 C.E.|
|Notable work(s)||al Mu'tamad Fī Usūl al Dīn, al-Aḥkām al-sulṭāniyya.|
Abū Yaʿlā Muḥammad ibn al-Ḥusayn Ibn al-Farrāʾ (April 990 – 15 August 1066), commonly known as al-Qāḍī Abū Yaʿlā or simply as Ibn al-Farrāʾ, was a Mujaddid and a great Hanbali Mujtahid scholar and one of the early Muslim jurists who played dynamic roles in formulating a systematic legal framework and constitutional theory on Islamic system of government during the first half of the 5th/11th Century in Baghdad.  From amongst his students was the great Imam Mahfūz al Kalwadhānī, another leading major Hanbali Mujtahid scholar.
al-Qāḍī Abū Yaʿlā authored many works, including:
- Kitāb al-muʿtamad fī uṣūl al-dīn
- al-Aḥkām al-sulṭāniyya
- Ibṭāl al-taʾwīlāt li-aḫbār al-ṣifāt
- al-ʿUdda fī uṣūl al-fiqh
- Abdul Azeez, Yusuf; Shah Suratman, Azmi; Salamon, Hussin; Awang, Ramli (2014). "Al-Qāḍī Abū Ya'lā: thoughts and influence on the development of legal theory of Islamic civilization and sciences of jurisprudence". UMRAN – International Journal of Islamic and Civilizational Studies. 1: 1. Retrieved 20 March 2016.