عنوان مقاله [English]
Enjoyment of the rewards of preserving (or memorizing) forty hadiths for the nation, which has been mentioned in the Prophetic narratives, has led to a type of hadith writings called 'Arba'een writings. This style among Shiites and Sunnis, since the first 'Arba'een has compiled in the second century AH until the writings in the present day, has passed its evolution in two different tracks; these writings can be divided in two types of thematic and documentary (sanad) 'Arba'een writings. This study investigated interactions between Shi'as and Sunnis in periods of ups and downs of Arba'een writing to achieve the status of a style of an evolved tradition writing. It shows that Sunnis firstly commenced compiling 'Arba'een books and before Shi'as they evolved its thematic and documentary types. It has begun by Shi'as through compiling virtues and usually continued in thematic type. In contemporary, the interest has been reduced among Sunnis, but Shiite authors have considered it continuously.