Hadith authenticity grades
Classical hadith scholars classify each narration into one of four primary grades. The grade determines whether a hadith can be used as evidence in matters of doctrine and law:
- Sahih (صحيح) — sound. A continuous chain of upright, precise narrators with no hidden defects and no contradiction with stronger reports.
- Hasan (حسن) — good. Meets sahih criteria except for a slight weakness in narrator precision. Still evidentiary.
- Da'if (ضعيف) — weak. A defect in the chain or text. Not authoritative for doctrine or legal rulings.
- Mawdu' (موضوع) — fabricated. Invented and falsely attributed to the Prophet ﷺ; rejected outright.
Bukhari and Muslim included only what their stringent criteria deemed sahih. The Sunan compilers (Abu Dawud, Tirmidhi, Nasa'i, Ibn Majah) and Musnad Ahmad included some weaker narrations, and Tirmidhi in particular graded each hadith explicitly after recording it.
Every major hadith collection is studied alongside one or more classical commentaries (sharh) that explain the chains, grade the narrations, and unpack the legal and theological implications. The principal commentaries for the Six Books are:
- Sahih al-Bukhari — Fath al-Bari by Ibn Hajar al-Asqalani (d. 852 AH), and Umdat al-Qari by Badr al-Din al-Ayni (d. 855 AH).
- Sahih Muslim — Al-Minhaj fi Sharh Sahih Muslim by Imam an-Nawawi (d. 676 AH).
- Sunan Abu Dawud — 'Awn al-Ma'bud by al-ʿAzim Abadi, and Badhl al-Majhud by Khalil Ahmad as-Saharanpuri.
- Jami at-Tirmidhi — Tuhfat al-Ahwadhi by al-Mubarakpuri.
- Sunan an-Nasa'i — Hashiyat as-Sindi.
- Sunan Ibn Majah — Ma Tamassu ilayhi al-Hajah by as-Sindi.
Ibn Hajar's Fath al-Bari is widely treated as the high-water mark of the genre — a chapter-by-chapter explanation of Sahih al-Bukhari that took him roughly 25 years to complete.
How to study these collections
Four practical guidelines for working through this library:
- Start curated. Begin with Riyad as-Salihin or An-Nawawi's 40 Hadith — short, thematically organized, and almost entirely sahih — before tackling the larger books.
- Read with translation, verify in Arabic. English renderings carry interpretation. Where authoritative meaning is at stake, consult the Arabic matn and a trusted commentary.
- Track the grade. Only sahih and hasan narrations are evidentiary in fiqh and ʿaqīdah. Da'if reports may be cited for moral encouragement but not for ruling on what is obligatory or forbidden.
- Read commentary alongside. Ibn Hajar's Fath al-Bari (on Sahih al-Bukhari) and an-Nawawi's Sharh Sahih Muslim are the classical commentaries every student returns to.
Frequently Asked Questions
What is a hadith?
A hadith is a recorded saying, action, or tacit approval of the Prophet Muhammad ﷺ. Each hadith has two parts: the isnad (the chain of narrators who transmitted the report) and the matn (the actual text of what was said or done). After the Quran, hadith form the second primary source of Islamic law, theology, and practice.
What are the six books of hadith (Kutub al-Sittah)?
The Kutub al-Sittah, or “Six Books,” are the six hadith collections Sunni scholars settled on as canonical by the 3rd century AH: Sahih al-Bukhari, Sahih Muslim, Sunan Abu Dawud, Jami at-Tirmidhi, Sunan an-Nasa'i, and Sunan Ibn Majah. Sahih al-Bukhari and Sahih Muslim are together known as the Two Sahihs (al-Sahihan), and a hadith both compilers narrate (muttafaq alayh) is treated as the highest grade of authenticity.
Which hadith collection is the most authentic?
Sahih al-Bukhari is regarded as the most authentic book after the Quran. Muhammad al-Bukhari evaluated over 300,000 reports and admitted only ~2,602 unique hadith into his Sahih based on the strictest criteria for narrator integrity, memory, and continuous chain. Sahih Muslim follows immediately after in rank; together they form the Two Sahihs.
What does sahih mean?
Sahih (صحيح) means “sound” or “authentic.” It is the highest grade of hadith and requires a continuous chain of upright, precise narrators from the Prophet ﷺ to the compiler, with no hidden defects (ʿillah) and no contradiction with stronger reports. The next grade down is hasan (good), then da'if (weak), then mawdu' (fabricated and outright rejected).
How many hadith are there in total?
There is no single fixed total because the same hadith often appears in multiple collections through different chains. Counting with repetition across these 14 books gives roughly 60,000–70,000 narrations; counting unique reports gives somewhere over 10,000. Musnad Ahmad alone contains nearly 28,000 reports.
Are all hadith in these collections authentic?
No — only Sahih al-Bukhari and Sahih Muslim restricted themselves to hadith their authors judged sahih. The Sunan collections (Abu Dawud, Tirmidhi, Nasa'i, Ibn Majah) and Musnad Ahmad include sahih, hasan, and da'if narrations, and the compilers often noted the grade explicitly. Tirmidhi was particularly transparent: he graded each hadith in his Jami after recording it.
What is the difference between a hadith and a Hadith Qudsi?
A regular hadith is the Prophet's own words. A Hadith Qudsi (sacred hadith) is one where the meaning is from Allah and the wording is the Prophet's — communicated by revelation but not part of the Quran itself. Hadith Qudsi are typically devotional in nature, dealing with Allah's mercy, the Day of Judgement, and the relationship between Creator and creation. There are roughly 40–100 well-authenticated Hadith Qudsi, depending on the compiler.
Is Sahih al-Bukhari more authentic than Sahih Muslim?
Sunni scholarly consensus places Sahih al-Bukhari above Sahih Muslim in authenticity because Bukhari required that two narrators be confirmed contemporaries who actually met (the condition of liqāʾ), while Muslim accepted contemporaneity alone (al-muʿāṣarah). A small minority of scholars — most famously Abu Ali al-Naysaburi and some Maghribi scholars — argued the reverse, citing Muslim's tighter chain organization. But the dominant view, articulated by Ibn Salah, an-Nawawi, and Ibn Hajar, is that Bukhari ranks first and Muslim second.
How did Imam al-Bukhari collect 600,000 hadith?
Bukhari did not collect 600,000 hadith in the sense of writing them down one by one. The figure (sometimes given as 300,000 or 600,000) represents reports he heard, evaluated, and memorized over roughly 16 years of travel — across Makkah, Madinah, Iraq, Egypt, Syria, and Khurasan. Of those, only ~2,602 unique hadith (and ~7,275 counting repeated chains) met his stringent criteria for inclusion in Sahih al-Bukhari. Most were rejected because of weakness in a single narrator, not because the report was fabricated.
What is the difference between Sahih, Sunan, Jami', and Musnad?
These are organizational genres, not authenticity grades. A Sahih (e.g., Bukhari, Muslim) restricts its content to hadith the compiler judged sound. A Sunan (e.g., Abu Dawud, Nasa'i, Ibn Majah) organizes hadith by jurisprudential chapter — purification, prayer, zakat — and may include sahih, hasan, and da'if reports. A Jami (e.g., Tirmidhi) covers all eight conventional topics of hadith: creed, rulings, etiquette, tafsir, biography, manners, asceticism, and tribulations. A Musnad (e.g., Ahmad) arranges hadith by the Companion who narrated them, regardless of subject.
