Scope and Organization of the Work

Lisan al-Mizan is organized alphabetically by narrator name, following the convention of Mizan al-I'tidal. The work covers narrators across a very broad range: those in the six canonical collections who were criticized despite being accepted, those in secondary collections, those in Sufi chains of transmission, those in historical and literary sources, and those whose narrations appear in doctrinal and theological works.

Ibn Hajar's treatment of narrators in Lisan al-Mizan is more varied in depth than in his other rijal works. For major narrators about whom a great deal of information exists, the entries can be very long, synthesizing multiple sources and tracking the evolution of scholarly opinion about the person. For minor or obscure narrators, the entries may be quite short, recording only the available biographical data and the criticism that prompted their inclusion.

A distinctive feature of Lisan al-Mizan is its coverage of narrators who appear in Sufi chains of transmission. The Sufi tradition preserved its own chains linking disciples to teachers across the generations, and many narrators in these chains are not found in the standard rijal works focused on the hadith collections. Ibn Hajar's inclusion of these narrators makes Lisan al-Mizan an important reference for the history of Sufism as well as for hadith criticism.

Ibn Hajar also includes narrators from Shia transmission chains, Jewish and Christian converts whose transmissions appear in historical and exegetical sources, and narrators from regions not well covered by earlier rijal works — including some from the far eastern and western reaches of the Islamic world. This breadth of coverage reflects his recognition that Islamic scholarship was a global enterprise even in the medieval period.

The work also covers individuals accused of theological deviation (bid'ah), even when their hadith transmissions might otherwise be acceptable. Ibn Hajar follows the nuanced approach of the classical hadith scholars in this regard: innovation in belief does not automatically disqualify a narrator, but when the innovation involved conscious promotion of heretical doctrines, it could warrant rejection of the narrator's transmissions.