The Rigorously Authenticated Hadith It is characterized by five conditions: 1- Uninterrupted chain of transmission 2- Moral integrity of narrators 3- Exactitude of the narrators 4- Devoid of irregularity, i.e., not contradicting a more reliable one. 5- Free from any blemish.
Rigorously Authenticated Hadith by Virtue of another It is a well-authenticated Hadith narrated by many methods which strengthen each other.
The Well-Authenticated Hadith The well-authenticated Hadith by its own virtue: It has an uninterrupted chain of transmission, and free of blemish and irregularity. Its narrators have moral integrity, but their exactitude is lesser than that of rigorously authenticated Hadith.
The well-authenticated Hadith by virtue of another: This is basically a weak Hadith, but narrated by multiple methods which support each other. However there must be no doubt of lying or viciousness of the narrators.
At-Tirmidhiyy differs with the other scholars of Hadith in the definition of the well-authenticated Hadith and the “well and rigorously authenticated” Hadith.
Types of Rejected Hadith (Weak Hadith) The weak Hadith is that which lacks one of the conditions set for the rigorously or well-authenticated Hadith. Its weakness and degree of unreliability vary according to the extent or the degree it lacks such conditions.
A Hadith is rejected because of: A- Loss in the chain of the Hadith transmission:
Incompletely Transmitted Hadith 1.Incompletely transmitted Hadith (Mursal): It does not state, in the end of its chain of transmission, the Companion who related it directly to the Prophet.
Suspended Hadith 2. Suspended Hadith (Mu`allq): From the beginning of its chain of transmission one or more, of the narrators, are successively not stated. (Some of the suspended Hadiths of Al- Bukhari and Muslim are exceptionally accepted.)
Problematic Hadith 3. Problematic Hadith (Mu`dil): Two successive narrators or more are missing.
Broken-Chain Hadith 4. Broken-Chain Hadith (Munqati`): This is one in which a narrator is missing in (one point or more of) the chain of transmission, or in which an unknown narrator is mentioned, but it is neither incompletely transmitted, suspended, nor problematic.
Interpolated Hadith 5. Interpolated Hadith (Mudallas): The chain includes a latent missing which was deliberately contrived by the narrator to conceal a weakness or disruption in the chain of narrators, so as to improve its presentation.
Among its types is the latent incompletely transmitted Hadith in which the narrator quotes some of his contemporaries although it has been proved that they never met nor heard from each other.
Defective Hadith 1. Defective Hadith (Mu`allal): This is one that embodies a defect causing its invalidation.
Incorporated Hadith 2. Incorporated Hadith (Mudraj): This is one in which the narrator incorporated his own words into the content, or false narrators into the chain of transmission.
Denied Hadith 3. Denied Hadith (Munkar): This is a Hadith that contradicts the narration of a more trustworthy narrator.
Irregular Hadith 4. Irregular Hadith (Shadh): This is one that was narrated by a trusted narrator, but differs from that of a more acceptable narrator, having better exactitude or greater number of narrations.
Inverted Hadith 5. Inverted Hadith (Maqlub): This is a Hadith which one of its narrators has rearranged the text or the chain of transmission.
Disordered Hadith 6. Disordered Hadith (Mudtarib): A Hadith narrated in contradictory ways, while none is preferred over the other due to their equal strength.
Misread or Corrupted Hadith 7. Misread or corrupted Hadith (Musahhaf, or Muharraf): This is one in which a word or more are changed in the content or in the chain of transmission, due to a change in the place of dots over (Arabic) letters or of the letter form.
Confused Hadith 8. Confused Hadith (Mukhtalit): This is one whose narrator is mistaken because of senility, impaired vision, or loss of references.
C- Impeaching the moral integrity of the narrator:
Disregarded Hadith 1. Disregarded Hadith (Matruk): This is one in which narrator is accused of lying, the Hadith is known only through him, and is against the general rules.
Forged Hadith 2. Forged Hadith (Mawdu`): This is one invented and falsely attributed to the Prophet. There are many motives behind forgery undertaken by enemies of Islam, political powers, factions, and others, but the scholars of Hadith managed to devise criteria to identify and refute forged Hadiths.