Jami' al-Usul fi Ahadith al-Rasul

Jāmiʿ al-Uṣūl fī Aḥādīth al-Rasūl (Arabic: جامع الأصول في أحاديث الرسول, lit. 'The Compendium of the Foundations in the Hadiths of the Messenger') is a multi-volume hadith collection compiled by the Islamic scholar Majd ad-Dīn Ibn Athir. It gathers and reorganizes narrations from the six canonical Sunni hadith collections, as well as other sources like the Muwatta Malik, organizing them thematically for ease of study and reference. This work is considered a cornerstone for hadith studies.