This paper presents an overview of an ancient theory of Sharʻīa law, which originated during the 14th century, and was founded by the Hanbali jurist Najm al-Dīn al-Ṭūfī. The theory of “benefit in the interest of the person” (utilitarian theory in the Sharʻīa law) is by all accounts a unique theory in its time, not only among Muslims but in jurisprudence in general. In a very concise and argumentative way, the author presented his assumption that the main theme of Sharʻīa law is the protection of benefits in the interest of persons and that this is the main goal.

Moreover, he advocates the theory that benefit (al-maṣlaḥah) is the main source of Sharʻīa law (al-ḥukm al-sharʻī) that the jurist must take into account. Consequently, any Sharʻīa evidence (al-dalīl al-sharʻī) is assessed primarily from the aspect of benefit or harm to the mukallaf („an adult subject to the obligation of Sharʻīa norms”). The basis of his work was the ḥadīth: Lā ḍarara wa lā ḍirāra (“No injury/harm shall be inflicted or reciprocated”), which is recorded  in ḥadīth collections, and which Imam al-Nawawī included in his famous work: al-Arbaʻīn al-nawawiyyah.

Key words: benefit, harm, debtor, Sharia sources, interpretation of law, Sharia law.