Who compiled the first Hadīth book? When it was written? What were the sources used?
The Hadith work written in early years of Islam is 'Mu'atta' of Imam Malik. The author of the book died in 179 AH. This is the compilation of the second century A.H. The sources of Hadīths mentioned in it, and also in other books, are narrators. Some of these narrators had narratives written with them.
(Translated into English by Abid Mahmood)