The sound report (sahih)

In Nuzhat al-Nazar Ibn Hajar defines the report sound in itself as "a solitary report transmitted by an upright narrator of complete accuracy, with a connected chain, free of hidden defect and anomaly". ² It is the first of four kinds of accepted report: sound in itself, sound through another, good in itself and good through another. ³ The editor, Nur al-Din 'Itr, counts these qualifiers — "in itself" and "through another" — among Ibn Hajar's choices that became standard after him. ⁴

• Upright ('adl): one with a settled disposition that keeps him to piety and decorum, piety meaning avoidance of bad deeds — association of others with God, open sin or reprehensible innovation. ³
• Accuracy (dabt): accuracy of memory, retaining what he heard so that he can recall it at will; and accuracy of the written record, keeping his book safe from the time he heard and corrected it until he transmits from it; "complete" marks the highest degree. ³
• Connected: a chain with no gap, each narrator having heard the report from his teacher. ⁵
• Hidden defect (mu'allal): one containing a concealed, damaging flaw. ⁵
• Anomalous (shadhdh): one in which a narrator contradicts someone weightier (see the anomalous and the denounced). ⁵

Sound reports differ in rank as these qualities differ in strength, since they produce the predominant probability on which soundness rests. ⁵ The highest rank includes what some masters called the soundest chains, such as al-Zuhri from Salim ibn 'Abd Allah ibn 'Umar from his father, Muhammad ibn Sirin from 'Abida ibn 'Amr from 'Ali, and Ibrahim al-Nakha'i from 'Alqama from Ibn Mas'ud; below them, Burayd ibn 'Abd Allah ibn Abi Burda from his grandfather from his father Abu Musa; below that, narrators whose solitary reports count as good, such as Muhammad ibn Ishaq from 'Asim ibn 'Umar from Jabir, and 'Amr ibn Shu'ayb from his father from his grandfather. ⁶ The view relied on is not to call any single chain absolutely "the soundest", though the sum of what the masters said shows these chains to be preferable to others. ⁷

• To these ranks belongs the precedence of what al-Bukhari and Muslim both give over what only one gives, and of what only al-Bukhari gives over what only Muslim gives. ⁸
• The majority declared al-Bukhari's Sahih the sounder, and no one is known to have stated the opposite; Abu 'Ali al-Naysaburi's "there is nothing under the sky sounder than Muslim's book" denies that anything is sounder, not that anything is equal; and some Maghribis' preference for Muslim's Sahih concerns its presentation and arrangement. ⁸
• He gives the grounds of al-Bukhari's precedence: in connection, al-Bukhari required proof that a narrator met his source at least once, while Muslim was content with contemporaneity; in uprightness and accuracy, Muslim's criticised narrators are more numerous; in anomaly and defect, fewer of al-Bukhari's reports were criticised. ⁹ He quotes al-Daraqutni: "But for al-Bukhari, Muslim would neither have come nor gone." ¹⁰
• The ranks then run: al-Bukhari, Muslim, what meets the conditions of both, of al-Bukhari, of Muslim, and what meets neither; a lower class may outrank a higher one through other indications, as when a well-known report in Muslim supported by indications is preferred to an absolutely singular one in al-Bukhari. ¹¹

If accuracy is lighter while the other conditions hold, the report is good in itself, and with multiple chains it is declared sound, because the combined form has a strength that makes up for the shortfall in the narrator's accuracy. ¹²