Nuzha an-Nadhar is one of the most essential books to study, in order to understand the rulings and grading of past scholars. Written by one of the most erudite scholars of the 9th century, Ibn Hajar (may Allah be pleased with him) had enough experience with all the verdicts which earlier scholars issued. After spending a decade of his life learning the book of ‘Allamah Ibn as-Salah, and related books, he was well versed in understanding the nomenclature used by earlier scholars.