ahadeeth have been divided into three main categories on the basis of reliability of the narrators and the degree of authenticity of the text:
1) al-sahih (sound):
a hadeeth that has come down through the virtuous and pious men of age and whose integrity is beyond doubt and therefore the chain of transmission (al-isnad) and the text (al-matn) are sound, furthermore its text doesn’t contradict any established belief of islam. they have grades:
a) those given by bukhari and muslim.
b) those given by bukhari alone.
c) those given by muslim alone.
d) those not given by either, but fulfil their shuroot (conditions set by them).
e) those which fulfil bukhari’s shuroot (conditions set by imam bukhari).
f) traditions sound in the opinion of other authorities.
2) al-hasan (good):
a hadeeth which is not considered quite as strong as a sahih hadeeth because of the fact that some of its narrators have been found to have a weaker memory in comparison to the narrators of a sahih hadeeth. they are however sufficient for establishing points of law.
3) al-da’eef or al-saqeem (infirm):
the moral excellence of narrators of this category of ahadeeth is questionable. these types of ahadeeth have various degrees keeping in view the defects in their reporters or the texts. allowance is made for using weak ahadeeth in dealing with advise, stories, and good behaviour. weak ahadeeth should not be used in dealings with matters of law, i.e. halal and haram.
with reference to the number of transmitters:
1) mutawatir (continuous):
a hadeeth reported by a large number of people at different times, which makes it impossible for any falsehood to enter it. this condition must be met in the entire chain from its source to its end.
2) mashoor (popular):
these are ahadeeth which were originally narrated in the first generation by two to four narrators. later (on their authority) these were narrated by several narrators.
3) aziz (rare):
a hadeeth that has been transmitted by not less then two persons from not less then two.
4) ghareeb (poor or strange):
a hadeeth that is narrated from only one companion or from a single person at a later stage. it may apply to the chain of transmission (al-isnad) or the text (al-matn) or both. with a little difference it is also known as fard with only one transmitter at each stage or which is transmitted by people of only one particular area and if it differs from what others report then this type of hadeeth is known as shaaz. if it differs from what people of greater authority transmit or if its transmitter is not of sufficient reliability to have his unsupported tradition accepted, it is rejected.
with reference to the nature of chain of transmission (al-isnad):
1) muttasil (connected):
a hadeeth with an unbroken chain traced back to the source. this has two kinds:
a) muttasil marfoo:
chain goes back to sayyidina muhammad.
b) muttasil mauqooq (restricted):
chain goes back to a sahabi (companion).
2) maqtu’ (intersected):
a hadeeth going back to a tabi’ee (successor). some experts have used it in the sense of munqati (disconnected) which has been used for a hadeeth that has a chain including unspecified people or one later then a tabi’ee, who claims to have heard it from someone having defective hearing. it is also used for one later then a tabi’ee quoting directly from a sahabi (companion); but commonly this term is used when there is a break in the chain of authority at any stage later then a tai’ee.
3) munfasil (separated):
it is applied to a hadeeth with several breaks in the chain.
4) mu’allaq (suspended):
when one or more names are omitted at the beginning of the isnad or when the whole chain is omitted it is called mu’allaq.
5) mursal (dropped):
a hadeeth in which a tabi’ee directly quotes from sayyidina muhammad, dropping the sahabi (companion) from the chain.
6) mu’allal or ma’lool:
a hadeeth that has some fault in the chain of transmission (al-isnad) or the text (al-matn).
with reference to special features of the text (al-matn) or the chain of transmission (al-isnad):
a hadeeth where the transmitters in an isnad use the same words or are of the same type or come from the same place. this types has two kinds:
a) musalsal al-half:
if in the chain of transmitters every one swears an oath regarding the authenticity of the text (al-matn).
b) musalsal al-yad:
if in the chain of transmitters each of the transmitters gives his hand to whom he transmits the hadeeth.
a hadeeth having a concealed defect in the isnad due to different reasons. different classification of this kind are as follows :
this defect may be pretending to hear a hadeeth from a contemporary while it may not be the case.
the authority quoted bears an unfamiliar name instead of the original and known name.
to omit a weak transmitter between sound ones.
3) mubham (obscure):
when a transmitter is named vaguely such as rajul (man) or ibn fulan (son of so and so) particularly when a father is not well known.
4) maqbul (transposed):
a hadeeth that is attributed to someone other then the real authority to make it acceptable ghareeb hadeeth.
5) mudhtarib (contradictory or confused):
it is used when two or more persons disagree with one another in their version of the hadeeth; they being people of equal status in piety, learning etc. the difference may affect the chain of transmission (al-isnad) or the text (al-matn). this nature of defect makes a hadeeth weak. when a man becomes knows as mudhtarib-ul-hadeeth, it means his traditions are confused.
with reference to acceptable traditions:
1) ma’roof (acknowledged):
it is applied to a weak hadeeth confirmed by another weak one, or it is a hadeeth superior in the text (al-matn) or chain of transmission (al-isnad) to a hadeeth known as munkar (ignored). it is also applied to a muhaddith (tradionist) who is reported by more then one transmitter, otherwise he is majhul i.e. unknown either as a person or his reliability.
2) maqbul (accepted):
it is hadeeth that fulfils the requirements and it is either sahih (sound) or hasan (good).
3) mahfuz (protected):
it applies to a hadeeth which, when compared to shaaz is considered of a greater weight and value.
with reference to rejected traditions:
1) munkar (ignored):
a hadeeth whose transmission is alone and differs from one who is reliable or is one who has not the standing to be accepted when alone.
2) mardud (rejected):
it is opposite of maqbul. more particular, it is a hadeeth from a single transmitter contradicting the authorities on the same material.
3) matruk (abandoned):
it is a hadeeth reported by such a transmitter suspected of falsehood or is openly wicked in speech and action or is guilty of carelessness or frequent wrong notions.
4) mawdu’ (fictitious):
this is the worst type of all, as the entire contents of it are fabricated having no truth in it.