A message arrives on your phone: "The Prophet said..." followed by a promise, and a request to forward it. Is it true? Muslim scholars built a whole science to answer exactly that question. In short: a sahih hadith has an unbroken chain of trustworthy and precise narrators with no oddity or hidden defect; a hasan hadith meets the same conditions with narrators a little less precise; a da'if hadith falls short of at least one condition; and a mawdu' report is fabricated and may not be attributed to the Prophet ﷺ at all. This guide explains these terms and the others you will meet, in plain language.
What are the isnad and matn of a hadith?
Every hadith has two parts. The isnad is the chain of people who passed it on: "A told me that B told him that C heard the Prophet ﷺ say...". The matn is the text itself, the words that were said or the action that was described.
Take the first hadith in Sahih al-Bukhari. Al-Bukhari heard it from al-Humaydi, from Sufyan ibn 'Uyaynah, from Yahya ibn Sa'id al-Ansari, from Muhammad ibn Ibrahim al-Taymi, from 'Alqamah ibn Waqqas, from 'Umar ibn al-Khattab, who heard the Prophet ﷺ say: "Actions are only by intentions." The names are the isnad; the saying is the matn.
Muslim scholars treated the chain as seriously as the text. Imam Muslim records in the introduction to his Sahih the words of 'Abd Allah ibn al-Mubarak: "The isnad is part of the religion; were it not for the isnad, anyone would say whatever he wished." He also records the saying of Muhammad ibn Sirin: "This knowledge is religion, so look carefully at whom you take your religion from." A hadith is judged by both parts: a strong chain with a text that clashes with stronger evidence still has a problem.
What makes a hadith sahih?
Sahih means sound or authentic. Scholars of hadith set five conditions, and all five must be met:
- A connected chain (ittisal). Each narrator heard it directly from the one before, with no missing link from the compiler to the Prophet ﷺ.
- Upright narrators ('adalah). Each person is a practising Muslim of sound character, known for honesty, not a sinner or a liar.
- Precise narrators (dabt). Each has a strong memory or careful written record, so that he passes on the words accurately.
- No oddity (shudhudh). The narration does not contradict what more reliable narrators reported.
- No hidden defect ('illah). Expert critics, comparing all the chains, have found no subtle flaw, such as a narrator who is said to have heard from someone he never met.
The last two conditions are why grading is a specialist's work. Only someone who has gathered many chains of the same hadith can see that one narrator added a word others did not, or that a chain that looks connected has a gap.
Some hadith are called sahih li-ghayrihi, "sahih because of others": a hasan hadith that becomes sahih because it is supported by other chains. The most famous sahih collections are those of al-Bukhari and Muslim, explained in our guide to the six books of hadith.
What is a hasan hadith, and how is it different from sahih?
Hasan means good. A hasan li-dhatihi ("hasan in itself") hadith meets all five conditions, except that one or more narrators, though honest, is a little less precise in memory than the narrators of a sahih hadith. It is still an accepted hadith, and it is used for rulings in Islamic law just as sahih hadith are.
A hasan li-ghayrihi ("hasan because of others") hadith starts as mildly weak, for example because a narrator had a weak memory, but is reported through several such chains that support one another. When the weakness is light and the chains are independent, they lift each other to hasan. When the weakness is severe, for example a narrator accused of lying, extra chains do not help.
Imam al-Tirmidhi made the term hasan widely known. In his Jami' you will often read hasan sahih. Scholars have explained this phrase in several ways: that the hadith has two chains, one hasan and one sahih, or that scholars differed over which grade it deserves. Either way it signals an accepted hadith.
What is a da'if hadith and what types are there?
Da'if means weak. A hadith is weak when it misses one or more conditions of hasan. Weakness has degrees: a slightly weak hadith is very different from one that is close to fabricated. The main types come from either a break in the chain or a problem with a narrator.
Breaks in the chain
- Mursal. A Tabi'i (a student of the Companions) says "The Prophet ﷺ said..." without naming the Companion he heard it from.
- Munqati'. One narrator is missing somewhere in the middle of the chain.
- Mu'dal. Two or more narrators in a row are missing.
- Mu'allaq. The compiler drops the start of the chain. Al-Bukhari does this in some chapter headings, and those reports are studied separately from his main connected hadith.
- Mudallas. A narrator hides a gap by using a vague word like "from" instead of "he told me".
The Hanafi position on mursal hadith
Here the schools differ, and the difference matters. In the Hanafi school, the mursal of a trustworthy narrator from the early generations is accepted and acted upon. The reasoning is simple: a reliable Tabi'i who says firmly "The Prophet ﷺ said" would not do so unless he was confident of his source; dropping the name usually shows his certainty, not doubt. The Maliki school holds a similar view, and it is reported from Imam Ahmad as well. Imam al-Shafi'i accepted the mursal only with supporting conditions, and many later hadith specialists classed it as weak. So when a Hanafi book uses a mursal hadith as evidence, it is following a principled method, not overlooking a weakness.
Problems with narrators
A hadith is weak when a narrator is unknown (majhul), has a poor memory, makes frequent mistakes, or is accused of lying. A weak narrator who contradicts reliable ones produces a munkar hadith. A narrator accused of lying produces a matruk (abandoned) one.
Mawdu': fabricated reports
A mawdu' report is not a weak hadith; it is not a hadith at all. It was invented and falsely attributed to the Prophet ﷺ. Narrating it as his saying is forbidden, except to warn people about it, because the Prophet ﷺ said that whoever lies about him deliberately should take his seat in the Fire (Sahih al-Bukhari, hadith 110). Scholars like Ibn al-Jawzi, al-Suyuti and 'Ali al-Qari wrote whole books listing such reports. Popular sayings such as "Love of one's homeland is part of faith" were judged by hadith critics to have no basis as words of the Prophet ﷺ.
What do mutawatir, mashhur, 'aziz and gharib mean?
These terms describe how many chains a hadith has, not directly how strong it is.
- Mutawatir. Reported by so many people at every level that it is impossible they all agreed on a lie. It gives certain knowledge. The Qur'an itself reached us this way, and "Whoever lies about me deliberately..." is a classic example of a mutawatir hadith.
- Ahad. Any hadith short of mutawatir. Most hadith are ahad. An authentic ahad hadith is accepted and acted upon.
- Mashhur. Reported through three or more chains at each level. Hanafi scholars of usul, using the term in their own slightly different sense, give the mashhur hadith a special strength between mutawatir and ahad, which affects how it is used alongside the Qur'an.
- 'Aziz. Reported through at least two chains at each level.
- Gharib. Reported through only one chain at some level.
A gharib hadith can still be sahih. "Actions are only by intentions" was narrated only by 'Umar, then only by 'Alqamah, then only by Muhammad ibn Ibrahim, then only by Yahya ibn Sa'id, after which it spread widely. It is gharib in its early chain and yet one of the most authentic hadith in Islam. Imam al-Tirmidhi often uses "gharib" this way, so the word alone is not a verdict of weakness.
What do marfu', mawquf and maqtu' mean?
These terms tell you whose words you are reading:
- Marfu' ("raised"). Attributed to the Prophet ﷺ: his words, actions or approval.
- Mawquf ("stopped"). The words or practice of a Companion, such as Ibn Mas'ud or 'A'ishah.
- Maqtu' ("cut off"). The words of a Tabi'i, such as al-Hasan al-Basri. Do not confuse it with munqati', which means a broken chain.
A mawquf report can be fully authentic as the saying of a Companion, but it is not a saying of the Prophet ﷺ. Sometimes a Companion says something that could only have come from revelation, such as details of the unseen; scholars then treat it as having the ruling of marfu'. The Hanafi school gives great weight to the statements of the Companions, especially those of 'Abd Allah ibn Mas'ud, whose students taught in Kufah.
How do scholars judge narrators in jarh wa ta'dil?
Jarh wa ta'dil means "criticism and accreditation". From the second century onwards, critics such as Shu'bah ibn al-Hajjaj, Yahya ibn Sa'id al-Qattan, Yahya ibn Ma'in, Ahmad ibn Hanbal and 'Ali ibn al-Madini examined thousands of narrators. They checked their honesty, compared their narrations with those of others, noted when their memory weakened in old age, and recorded who met whom.
Their judgements were gathered into books such as Ibn Abi Hatim's al-Jarh wa at-Ta'dil, al-Dhahabi's Mizan al-I'tidal and Ibn Hajar's Taqrib at-Tahdhib. The Taqrib gives each narrator a short grade on a scale. Simplified, it runs like this:
- Highest. Thiqah (reliable), thiqah thabt (reliable and exact).
- Middle. Saduq (truthful, usually leading to hasan).
- Weak. Da'if, layyin (soft), majhul (unknown).
- Rejected. Matruk (abandoned), kadhdhab (liar), wadda' (fabricator).
Critics did not spare anyone: some judged their own relatives weak. That honesty is why their work is trusted.
How do you read a hadith reference like muttafaq 'alayh?
A reference such as "Sahih al-Bukhari, hadith 1" tells you the book and the number. Be aware that different editions number hadith differently, so the same hadith can carry different numbers in two printings. A careful reference often adds the chapter, or the edition used.
- Muttafaq 'alayh. Reported by both al-Bukhari and Muslim from the same Companion. This is the strongest common label.
- "Reported by al-Arba'ah". In books such as Ibn Hajar's Bulugh al-Maram, this means the four Sunan: Abu Dawud, al-Tirmidhi, an-Nasa'i and Ibn Majah.
- "Reported by al-Khamsah" and "al-Sab'ah". In the same book, the five are Ahmad and the four Sunan; the seven are Ahmad and all six books.
- A grade after the reference. "Al-Tirmidhi said: hasan sahih" or "graded da'if" tells you its strength. A reference to a Sunan without a grade only tells you where the hadith is.
Can weak hadith be used for virtues, and how should you check forwards?
Many scholars, including the majority of jurists and many hadith experts, allowed acting on a weak hadith in matters of virtue and encouragement (fada'il al-a'mal), not in beliefs or rulings. Ibn Hajar's conditions, passed on by his student al-Sakhawi, are well known:
- Not severely weak. It is not from a liar, an accused liar or a narrator who makes gross errors.
- Under an established principle. The deed it encourages is already good according to authentic evidence.
- No firm belief in it. The person does not believe the Prophet ﷺ definitely said it, and acts out of caution.
Imam Abu Hanifa is widely reported to have given precedence to a hadith with light weakness, and to the sayings of the Companions, over analogy (qiyas), which shows how seriously the school took narrations. But none of this allows spreading fabricated reports, or presenting a weak hadith as certain. Imam Muslim reports in the introduction to his Sahih that the Prophet ﷺ said it is enough of a lie for a person to narrate everything he hears.
Before you press forward
Ask for the book and the number. Look for the grade, not just the collection. Be wary of exact numbers of reward, threats for not sharing, or promises that sound too neat. If you cannot verify it, do not forward it. Share a verse of the Qur'an or a well-known authentic hadith instead.
For a trusted set of authentic hadith to start with, read our 40 Hadith of Imam an-Nawawi, see how these rules apply to popular claims in surah benefits: what is authentic and what is not, and look up unfamiliar words in our Islamic glossary. If you would like to study with a teacher, our courses are open to all ages.
Sources
- Sahih al-Bukhari, hadith 1: actions are only by intentions.
- Sahih al-Bukhari, hadith 110: whoever lies about the Prophet deliberately, let him take his seat in the Fire.
- Sahih Muslim, Introduction: the sayings of Ibn al-Mubarak and Ibn Sirin on the isnad, and the hadith that it is enough of a lie to narrate everything one hears.
- Ibn al-Salah, Muqaddimah ('Ulum al-Hadith), on the definitions of sahih, hasan and da'if.
- Ibn Hajar al-'Asqalani, Nukhbat al-Fikar and Taqrib at-Tahdhib, on hadith categories and narrator grades.