The science of classifying and grading a hadith based on its authenticity evolved over a period of time corresponding to the various other developments taking place in hadith literature. It also grew out of a need to combat external damaging influences from affecting the truth as it reaches us. Though today, the categories of saheeh, hasan and daeef hadith have taken on well-defined meanings and they seem to render almost a universal understanding amongst scholars all over the globe, a few centuries ago, different scholars had different means of implying what they thought was most authentic and so on. It is this ambiguity in the jargon of the different hadith scholars that has led to a difference in the opinions of contemporary scholars on what they implied by certain terms. In the following pages, we shall discuss in some detail the meaning of a weak hadith and the issue of the permissibility of quoting weak hadith.
Definition of a weak hadith
A rejected hadith is one which does not meet the conditions for being sahih or hasan, i.e., the hadith is lacking in any of the following conditions for it to be accepted on its own merit.
(i) It’s isnad must be complete,
(ii) The narrators in the various levels of the chain must be known for their integrity and piety,
(iii) The narrators must be known for their proficiency,
(iv) The narration must not contradict another stronger, more established narration, and
(v) There must be no hidden faults within the narration.
A rejected hadith can further be divided into three categories: a weak hadith, a very weak hadith or a fabricated hadith.
A weak hadith can be rendered its weakness due to a number of reasons including a break in any level of the chain, a known weakness in the memory if the narrator, ambiguity surrounding a narrator and so on. The degree of seriousness of each defect and the number of defects will lead a hadith to being closer to an authentic hadith or a fabricated hadith.
While it is unanimously agreed upon that a fabricated hadith is to be rejected outright, there is a difference of opinion amongst scholars regarding the permissibility of stating and acting upon a hadith which has been rendered weak due to a minor defect like one of the narrators having a weak memory.
(1) The first opinion which has been attributed to Ahmad, Abu Dawood, Shafi’ee and others is that a weak hadith can be used without any restrictions. This is due to their well known practice of preferring weak hadith over personal opinion. Also it has been recorded of Abu Dawood that he would resort to using weak hadith if he could not find a sahih hadith on the particular issue.
However, several scholars have postulated theories to explain this. Some scholars say that Ahmad would prefer a weak hadith over a wrong analogy that is based on principles opposed to the Qur’an or Sunnah or an analogy that is made where no true common characteristics are shared between the two cases. In this case, Ahmad would use a weak hadith and reject the analogy.
Another theory that was brought forward by Ibn Taymiyyah and others was that this was before the time of Tirmidhi who first defined the term ‘hasan’ and what Imam Ahmad actually meant by weak hadith did not correspond to the current definition of a weak hadith. Hence he was actually referring to a hasan hadith and that was acceptable to use by many early scholars.
Abu Dawood on the other hand, mentioned in his work that any hadith regarding whose authenticity he does not make a comment on is regarded by him to be acceptable (saalih). Ibn Hajar has explained through examples that the hadith which Abu Dawood used were to be used for supporting evidence itself or could be supported by other evidence which shows that he did not use very weak hadith. Hence, though it is known of these scholars to resort to ‘weak’ hadith, what they meant by weak hadith is most probably just a lower form of hasan hadith.
(2) The opinion followed by a majority of scholars is that weak hadith can be related and acted upon provided they meet with certain conditions. It is to be noted here that the weak hadith related to the Islamic creed, those which elaborate upon the Names and attributes of Allah (subhanu wa ta’aala), those which relate what is forbidden and permissible are not to be used as legal proofs nor acted upon. The weak hadith that are talked about here are those exhorting people to do good and forbidding them from evil. Ibn Hajar summarized the different conditions as follows:
- The hadith must not be very weak or fabricated.
- The hadith may not be used as an evidence for something that is not already established by the Qur’an or more authentic ahadith.
- If the hadith mentions a certain reward for a particular deed then that reward must not be expected by the doer but he must do the deed out of fear and love for Allah and hope for some reward from Allah.
- Subhi as-Saalih mentioned another condition not mentioned by other scholars. He said that the hadith must not contradict stronger narrations. However this condition seems to be a natural consequence of the second condition mentioned above. 
While this opinion seems to be the preponderant view amongst scholars, it would be wrong to claim that there is an actual consensus amongst the scholars regarding this issue.
Amongst the criticism raised against the second opinion is that accepting weak hadith when it comes to the recommendation of some deeds inevitably leads to that act being given precedence over other deeds whose importance and rewards are more strongly established in the Qur’an and Sunnah.
Also, the conditions to be applied for the second opinion have become more or less obsolete as scholars who specialize in differentiating between weak and very weak hadith have dwindled. More often than not, fabricated and very weak hadith are spread amongst the masses under the guise that it is a weak hadith and is hence acceptable. In this manner, people have become negligent in what they narrate about the Prophet (sal Allahu alaihi wasallam).
For those who insist on following this opinion, they must ensure that all the conditions mentioned are fulfilled. Also, it is the responsibility of the one narrating the weak hadith to explicitly mention to his audience that it is a weak hadith that he is relating since if he relates it without mentioning the weakness it may lead people to assume it is authentic, it is like attributing to the Prophet something which is not confirmed to come from him. The gravity and consequences of such an act shall be discussed below.
(3) The third view which is the most popular view amongst those scholars who have studied this matter and the view of Bukhari, Muslim, al Khattabi and others is that weak hadith must not be resorted to in any situation. They argue that the authentic narrations are sufficient for one and one may not needlessly rely upon weak hadith and expose oneself to the punishment of Allah which has been clearly warned against in the following narrations.
Salamah ibn al-Akwa` (radiyallaahu anhu) and others narrated that Allaah’s Messenger said:
“Whoever ascribes to me what I have not said, let him occupy his seat in the fire of hell!”
Aboo Qataadah al-Ansaaree (radiyallaahu anhu) said: “I heard the Messenger of Allaah saying upon this pulpit:
“O people! Beware of relating a lot of hadeeths about me! Whoever says anything about me must not say except the truth, for whoever ascribes to me what I have not said, let him occupy his seat in the fire of hell!””
Ibn Maajah (35) and graded authentic by al-Haakim (1/111)
Also, Samurah ibn Jundub and al-Mugheerah ibn Shu’bah (radiyallaahu anhumaa) narrated that Allaah’s Messenger said:
“Whoever relates from me a hadeeth which is thought to be a lie (or which he thinks is a lie), then he is (also) one of the liars.”
Waathilah ibn Al-Asqa`(radiyallaahu anhu) narrated that the Allaah’s Messenger said:
“Verily, one of the worst lies is to ascribe to me what I have not said!”
al-Bazzaar (C.f. Al-Majma`, 1/144; As-Saheehah, 7/173-174)
Hence, it becomes clear that the punishment for attributing something to the Prophet something he did not say is very harsh and when a scholar says a hadith is weak he implies that it is not confirmed that the Prophet did, indeed, state such words.
The argument for following this third opinion can be eloquently summarized in the words of Albani in his Sifat Salat an Nabi:
I believe that what we have in the way of confirmed hadith is sufficient and we do not have to resort to weak hadith. [Weak hadith] do not aid us – and there is no difference in this point- except through conjecture. And conjecture is nothing but weakness as Allah says, “And they have no knowledge thereof. They follow but a guess and lo! A guess can never take the place of truth.” (An Najm: 27) And the Prophet said, “Avoid conjecture as conjecture is the most deceitful speech (Recorded by Bukhari and Muslim). And we cannot worship Allah by acting according to conjecture. In fact, the Prophet has prohibited us from it as he said, “Beware of the hadith related on my authority, except for what you are knowledgeable of.” (Sahih, recorded by al-Tirmidhi, Ahmad and ibn Abu Shaiba.) In that statement, he disallowed us to relate weak reports. It must be even more so the case that it is prohibited to act in accordance with such reports.”
Thus it becomes clear that the best opinion to follow amongst the three is to avoid stating and acting upon weak hadeeth. The first opinion does not seem to be the actual opinion of those it is attributed to. The second opinion, though popular, is beset with a lack of sound evidence for it and is impractical as there are very few people who are qualified to make sure that the conditions are fulfilled. The safest and most sound view is then, to avoid weak hadith and to rely upon authentic narrations only.
 It must be noted that depending on the level of proficiency and integrity of the narrators, a narration which fulfills all these conditions is will either be sahih or hasan on its own merit. (sahih lithaatihi and hasan lithaatihi). However, a weak hadith can be raised to the level of hasan if there is strong supporting evidence to allow for such and such a hadith is said to be on the level of hasan lighairihi.
 Ibn Hajar, al Nukat, vol 1, p 436 as cited in Zarabozo, Commentary on the Forty Hadeeth, vol 1, p 82
 Ibn Taymiyah, Sharh Hadith, Maktaba as Salaam al Alamiyyah, 1981, p 11 as cited in Zarabozo, Commentary on the Forty Hadeeth, vol 1, p 84
 Ibn Hajar, Tabyeen al-Ajab, Beirut, Dar ul Ilm al Malayeenm 1981, p 212 as cited in Zarabozo, Commentary on the Forty Hadeeth, vol 1, p 87