, chain of authorities, an essential part of the transmission of a tradition. Little need of this was realized in the earliest times, but as the first century of Islam advanced, the need for stating one’s authority developed. The collections of traditions which were compiled mainly in the 3rd/9th century onwards give complete isnād s.
See al-d̲j̲arḥ wa ’l-taʿdīl and ḥadīt̲h̲ . Add to the Bibliographies Fazlur Rahman, Islam, London 1966, chap. 3 passim and Nabia Abbott, Studies in Arabic literary papyri II, Qurʾanic commentary and tradition, Chicago 1967, see Index.