Musnad Iman Ahmed bin Hanbal(6 Volumes set)

One of the greatest compilations of the sunnah and books of hadith is the Musnad by Imam Ahmad bin Hanbal, which is organized into compilations of the hadiths narrated by each Companion (Sahabi), starting with the ‘asharah mubashsharah (“the ten who were promised Paradise”). This highlights their status and the efforts they made to preserve the ahadeeth of the Messenger of Allah (S).