We have, Without doubt, sent down the message: and we will assuredly guard it (from corruption). (Qur'ân 15:9) The promise made by Allah (Ta'aalaa) in Qur'ân 15:9 is obviously fulfilled in the undisputed purity of the Qur'ânic text throughout the fourteen centuries since its revelation. However, what is often forgotten by many Muslims is that the divine promise also includes, by necessity, the Sunnah of the Prophet (peace be upon him), because the Sunnah is the practical example of the implementation of the Qur'ânic guidance, the wisdom taught to the Prophet (peace be upon him) along with the scripture, and neither the Qur'ân nor the Sunnah can be understood correctly without the other. Allah (Ta'aalaa) preserved the Sunnah by enabling the companions and those after them to memorize, write down and pass on the statements of the Prophet (peace be upon him), and the descriptions of his way, as well as to continue the blessings of practicing the Sunnah. Later, as the purity of the knowledge of the Sunnah became threatened, Allah (Ta'aalaa) caused the Muslim Ummah to produce individuals with exceptional memory skills and analytical expertise, who travelled tirelessly to collect thousands of narrations and distinguish the true words of prophetic wisdom from those corrupted by weak memories, from forgeries by unscrupulous liars, and from the statements of the large number of Ulama (scholars), the companions and those who followed their way. All of this was achieved through precise attention to the words narrated, and detailed familiarity with the biographies of the thousands of reporters of hadeeth. The methodology of the expert scholars of hadeeth in assessing the narrations and sorting out the genuine from the mistaken and fabricated, for ms the subject matter of the science of hadeeth. In this article a brief discussion is given of the terminology and classifications of hadeeth. Components of Hadeeth A Hadeeth is composed of three parts Matn (text), isnaad (chain of reporters), and taraf (the part, or the beginning sentence, of the text which refers to the sayings, actions or characteristics of the Prophet (peace be upon him), or his concurrence with others action). The authenticity of the hadeeth depends on the reliability of its reporters, and the linkage among them. Classifications of Hadeeth A number of classifications of hadeeth have been made. Five of these classifications are briefly described subsequently. According to the reference to a particular authority Four types of hadeeth can be identified. Qudsi - Divine; a revelation from Allah (the Exalted); relayed with the words of the Prophet (peace be upon him). Marfu - elevated; a narration from the Prophet (peace be upon him), e.g. I heard the Prophet (peace be upon him) saying ...[or, I saw the Prophet doing so and so... , or mentioning things that were done and the Prophet approved them, or describing anything of the Prophet (self, morals, or behaviors) Asaala website] Mauquf- stopped: a narration from a companion only, e.g., we were commanded to ... [Asaala website says: If the commander is other than the Prophet, so Yes , but if it was him so, No, as it is also a type of Marfu' which is called " Marfu' Hukman (has the ruling of Marfu'), while the Mauquf is the saying of the Sahaabee (companion) e.g. Ibn abbaas said:..... without attributing to the Prophet (peace be upon him)] Maqtu' - severed: a narration from a successor [.. (of the companions i.e. a Taabi'ee) or a follower of the Taabi'un while the narration has no link with a sahaabee. "Asaala website" ] According to the links of Isnaad - interrupted or uninterrupted Six categories can be identified. Musnad - supported: a hadeeth which is reported by a traditionalist, based on what he learned from his teacher at a time of life suitable for learning; similarly - in turn - for each teacher until the isnaad reaches a well known companion, who in turn, reports from the Prophet (peace be upon him). Muttasil - continuous: a hadeeth with an uninterrupted isnaad which goes back only to a companion or successor [Taabi'ee]. [an uninterrupted isnaad (meaning: Each narrator has heard from the one he narrates from) which goes back to the Prophet, a companion or others. "Asaala website" ] Mursal - hurried: if the link between the successor and the Prophet (peace be upon him) is missing, e.g. when a successor says "The Prophet said...". Munqati' - broken: is a hadeeth whose link anywhere before the successor (i.e., closer to the traditionalist recording the hadeeth) is missing. [a hadeeth that its isnaad was not linked (interrupted) because of the inconsecutive omission of a reporter or more in one location or more. "Asaala website" ] Mu'adal - perplexing: is a hadeeth whose reporter omits two or more consecutive reporters [in one location and within the hadeeth] in the isnaad. Mu'allaq - hanging: is a hadeeth whose reporter omits the whole isnaad and quotes the Prophet (peace be upon him) directly (i.e., the link is missing at the beginning) [Mu'llaq: is omitting (from the beginning of the isnaad) one reporter or more (up to the whole isnaad)consecutively "Asaala website" ] According to the number of reporters involved in each stage of Isnaad Five categories of hadeeth can be identified: Mutawaatir - Consecutive: is a hadeeth which is reported by such a large number of people that they cannot be expected to agree upon a lie, all of them together. Aahad - isolated: is a hadeeth which is narrated by people whose number does not reach that of the mutawaatir. It is further classified into: Mash'hur - famous: hadeeth reported by more than two reporters. [by three or more reporters "Asaala website" ] Aziz - rare, strong: at any stage in the isnaad, only two reporters are found to narrate the hadeeth. Ghareeb - strange: At some [at any stage; either all stages , some stage or even one stage "Asaala website"] of the Isnaad, only one reporter is found relating it. According to the nature of the text and isnaad Mutawatir - Consecutive: is a hadeeth which is reported by such a large number of people that they cannot be expected to agree upon a lie, all of them together. Munkar - denounced: is a hadeeth which is reported by a weak narrator, and whose narration goes against another authentic hadeeth. Mudraj - interpolated: an addition by a reporter to the text of the hadeeth being narrated According to the reliability and memory of the reporters This provides the final verdict on a hadeeth - four categories can be identified: Saheeh - sound. Imam Al-Shaafi'ee states the following requirements for a hadeeth, which is not mutawaatir, to be acceptable "each reporter should be trustworthy in his religion; he should be known to be truthful in his narrating, to understand what he narrates, to know how a different expression can alter the meaning, and to report the wording of the hadeeth verbatim, not only its meaning". Hasan - good: is the one where its source is known and its reporters are unambiguous. [There are other definitions one can refer to in the books of Mustalah Alhadeeth (Hadeeth Terminology) "Asaala website"] DA'EEF - weak: a hadeeth which fails to reach the status of hasan. Usually, the weakness is: a) one of discontinuity in the isnaad, in which case the hadeeth could be - according to the nature of the discontinuity - Munqati' (broken), Mu'allaq (hanging), Mu'dal (perplexing), or Mursal (hurried), or b) one of the reporters having a disparaged character, such as due to his telling lies, excessive mistakes, opposition to the narration of more reliable sources, involvement in innovation, or ambiguity surrounding his person. [also; lack of memorization and preciseness "Asaala website" ] Maudu' - fabricated or forged: is a hadeeth whose text goes against the established norms of the Prophet's sayings, or its reporters include a liar. Fabricated hadeeth are also recognized by external evidence related to a discrepancy found in the dates or times of a particular incident.