Ahl al-Bayt in the context of "Sunnah"

Hadith is the Arabic word for a 'report' or an 'account [of an event]' and refers to the Islamic oral tradition of anecdotes containing the purported words, actions, and the silent approvals of the Islamic prophet Muhammad or his immediate circle (companions in Sunni Islam, Ahl al-Bayt in Shiite Islam).

Each hadith is associated with a chain of narrators (isnad), a lineage of people who reportedly heard and repeated the hadith from which the source of the hadith can be traced. The authentication of hadith became a significant discipline, focusing on the isnad (chain of narrators) and matn (main text of the report). This process aimed to address contradictions and questionable statements within certain narrations. Beginning one or two centuries after Muhammad's death, Islamic scholars, known as muhaddiths, compiled hadith into distinct collections that survive in the historical works of writers from the second and third centuries of the Muslim era (c. 700−1000 CE).

The holiest sites in Islam are located in the Middle East. While the significance of most places typically varies depending on the Islamic sect, there is a consensus across all mainstream branches of the religion that affirms three cities as having the highest degree of holiness, in descending order: Mecca, Medina, and Jerusalem. Mecca's Al-Masjid al-Haram (including the Kaaba), Al-Masjid an-Nabawi in Medina, and Jerusalem's Al-Aqsa Mosque are all revered by Muslims as sites of great importance.

After the consensus on the first three sites as well as further sites associated with the family of Muhammad, there is a divergence between Sunni Muslims and Shia Muslims on the designation of additional holy sites. Even within each sect, there are disputes as to whether any uniquely holy cities exist apart from the aforementioned three. For Sunnis that argue that there are, sites associated with the Rashidun, other Companions of Muhammad, and Biblical prophets often hold a high level of significance (see holiest sites in Sunni Islam). In particular, the Umayyad Mosque in the city of Damascus and the Ibrahimi Mosque in the city of Hebron have held interchangeable significance as the fourth and fifth-holiest Islamic sites, respectively, for many Sunni Muslims. For Shias, sites associated with the Imamah hold a high level of significance (see holiest sites in Shia Islam).

In Shia Islam, the Imamah (Arabic: إمامة) is a doctrine which asserts that certain individuals from the lineage of the Islamic prophet Muhammad are to be accepted as leaders and guides of the ummah after the death of Muhammad. Imamah further says that Imams possess divine knowledge and authority (Ismah) as well as being part of the Ahl al-Bayt, the family of Muhammad. These Imams have the role of providing commentary and interpretation of the Quran as well as guidance.

The ghulāt (Arabic: غُلَاة, lit. 'exaggerators, extremists') were a branch of early Shi'a Islam. The term mainly refers to a wide variety of extinct Shi'i sects active in 8th- and 9th-century Kufa in Lower Mesopotamia, and who, despite their sometimes significant differences, shared several common ideas. These common ideas included the attribution of a divine nature to the Imams, metempsychosis (the belief that souls can migrate between different human and non-human bodies), a particular gnostic creation myth involving pre-existent 'shadows' (azilla) whose fall from grace produced the material world, and an emphasis on secrecy and dissociation from outsiders. They were named ghulat by other Shi'i and Sunni Muslims for their purportedly "exaggerated" veneration of Muhammad (c. 570–632) and his family, most notably Ali (c. 600–661) and his descendants, the Imams.

The ideas of the ghulat have at times been compared to those of the late antique gnostics, but the extent of this similarity has also been questioned. Some ghulat ideas, such as the notion of the occultation (ghayba) and return (raj'a) of the Imam, have been influential in the development of Twelver Shi'ism. Later Isma'ili Shi'i authors such as Ja'far ibn Mansur al-Yaman (died c. 957) and Abu Ya'qub al-Sijistani (died after 971) also adapted ghulat ideas to reformulate their own doctrines. The only ghulat sect still in existence today are the Alawites, historically known as Nusayris after their founder Ibn Nusayr (died after 868).

Sharifism was the system in pre-colonial Morocco in which the shurafā'—descendants of the Islamic prophet Muhammad (through his grandson Hasan ibn Ali, in the case of Morocco)—held a privileged religious and political position in society. Those who claimed this lineage were regarded as a kind of nobility and were privileged, in the words of Sahar Bazzaz, "as political agents, as interlocutors between various sectors of society, and as would be dynasts of Morocco". They were additionally believed to possess baraka, or blessing power. Claiming this lineage also served to justify authority; the Idrisi dynasty (788–974), the Saadi dynasty (1510–1659), and the 'Alawi dynasty (1631–present) all claimed lineage from Ahl al-Bayt.

Husayn ibn Ali (Arabic: الحسين بن علي, romanized: al-Ḥusayn ibn ʿAlī; 11 January 626 – 10 October 680 CE) was a social, political and religious leader in early medieval Arabia. The grandson of the Islamic prophet Muhammad and an Alid (the son of Ali ibn Abi Talib and Muhammad's daughter Fatima), as well as a younger brother of Hasan ibn Ali, Husayn is regarded as the third Imam in Shia Islam after his brother, Hasan, and before his son, Ali al-Sajjad. Husayn is a prominent member of the Ahl al-Bayt and is also considered to be a member of the Ahl al-Kisa and a participant in the event of the mubahala. Muhammad described him and his brother, Hasan, as the leaders of the youth of paradise.

During the caliphate of Ali, Husayn accompanied him in wars. After the assassination of Ali, he obeyed his brother in recognizing the Hasan–Mu'awiya I treaty, despite it being suggested to do otherwise. In the nine-year period between Hasan's abdication in AH 41 (660) and his death in AH 49 or 50 (669 or 670), Hasan and Husayn retreated to Medina, trying to keep aloof from political involvement for or against Mu'awiya I. After the death of Hasan, when Iraqis turned to Husayn, concerning an uprising, Husayn instructed them to wait as long as Mu'awiya was alive due to Hasan's peace treaty with him.