Arbaʿīn

Forty — referring both to the specific number of hadiths in the collection and to the tradition of compiling forty hadiths on a theme, rooted in a narration about the merit of preserving and transmitting the Prophet's teachings. Al-Nawawi selected forty-two to ensure comprehensiveness without violating the spirit of the tradition. The practice of compiling arba'in reflects Islam's understanding that the number forty carries spiritual significance — appearing in Quranic references to periods of spiritual formation — and that systematically preserving forty core teachings is a service of lasting benefit to the Muslim community across generations.

As understood in the classical tradition of Imam al-Nawawī and the scholars of his school.