In Islam, a hadith (حديث‎) is an account of the words or actions of the Prophet Muhammad, which are regarded as a special form of religious law. It is considered to be an important source of Islamic law and religious guidance. The word hadith is derived from the Arabic word dhīf, which means “he that gives knowledge.” In the hadith, the Prophet is said to have delivered knowledge to his followers through his actions, words, and miracles. It is also reported that the Prophet spoke in a peculiar way and that the hadith are collected in different ways.

In general, hadith are divided into two categories: those that are sahih (authentic), and those that are hasan (good). The word “sahih” is derived from the Arabic word “sahy”, which means “he that gives” or “gives knowing”. A hadith is considered to be authentic if the person who reported it had a good reason for telling the truth, and did not have a motive to falsify the account. The word “hasan” is derived from the Arabic word “hasad”, which means “the truth”. A hasan account is considered to be good if the person who reported it did not have a motive to falsify the account.

Some hadith are also called da’if (weak), because they are not certain about the reliability of the source.