Hadith studies ( ʻilm al-ḥadīth "science of hadith",also science of hadith, or science of hadith criticism or hadith criticism) consists of several religious scholarly disciplines used by Muslim scholars in the study and evaluation of the Islamic hadith—i.e. the record of the words, actions, and the silent approval of the Islamic prophet, Muhammad. Determining authenticity of hadith is enormously important in Islam because along with the Quran, the Sunnah of the Islamic prophet—his words, actions, and the silent approval—are considered the explanation of the divine revelation (wahy), and the record of them (i.e. hadith) provides the basis of Islamic law (Sharia). In addition, while the number of verses pertaining to law in the Quran is relatively few, hadith give direction on everything from details of religious obligations (such as Ghusl or Wudu, ablutions for salat prayer), to the correct forms of salutations, and the importance of benevolence to slaves. Thus the "great bulk" of the rules of Islamic law are derived from hadith, rather than the Quran. There are three primary ways to determine the authenticity (sihha) of a hadith: by attempting to determine whether there are "other identical reports from other transmitters"; determining the reliability of the transmitters of the report; and "the continuity of the chain of transmission" of the hadith. Traditional hadith studies has been praised by some as "unrivaled, the ultimate in historical criticism", and heavily criticized for failing to filter out a massive amount of hadith "which cannot possibly be authentic". Definition It has been described by one hadith specialist, Jalal al-Din al-Suyuti (d. 911 A.H/ 1505 C.E), as the science of the principles by which the conditions of both the sanad, the chain of narration, and the matn, the text of the hadith, are known. This science is concerned with the sanad and the matn with its objective being distinguishing the sahih, authentic, from other than it. Ibn Hajar al-Asqalani said the preferred definition is: knowledge of the principles by which the condition of the narrator and the narrated are determined. Types Some of the disciplines in the science of hadith, according to scholar İsmail Lütfi Çakan, include: the "study of the circumstances surrounding the genesis of each hadith," i.e. the reasons for why the hadith was uttered; the study of the gharib al-hadith, whose works provide "a kind of hadith glossary" of uncommon words found in hadith; the study of ilel al-hadith, which