The Holy Family of the Greatest Prophet (S.A.W.)
Traditionally and literally, the "Ahl al-Bayt" or "the members of the household" and the family of a man are those who live as members in the small society of his house such as his wife, son, daughter, and servant living within the housing complex of the houseowner.
Sometimes, the meaning of the Ahl al-Bayt is generalized to include close relatives such as father, mother, sister, children, uncle, father's sister, maternal aunt, and their children.
However, the meaning of "the Ahl al-Bayt (AS)" of the Holy Prophet (SA), expressed in the Holy Qur'an and ahadith, is not in line with the two preceding definitions. According to successive ahadith related through general and specific channels, "the Ahl al-Bayt" is a name granted as a gift to specially include the Holy Prophet (SA) and the respectable ones, 'Ali (AS), Fatimah (AS), al-Hasan (AS), and al-Husayn (AS). Therefore, on this basis, the other members of the Prophet's household and his relatives (although they are traditionally and literally considered as members of his household) are not covered by this definition. Even Khadijah al-Kubra, who was the most respectable wife of the Holy Prophet (SA) and the mother of Fatimah (AS). and also Ibrahim, who was the consanguineous son of the Holy Prophet (SA) and who had the greatest honour, are not included in "Ahl al-Bayt (AS)" of the Holy Prophet (SA).
Indeed, according to these and other ahadith, nine infallible Imams out of twelve infallible Imams, who are the sons and offsprings of Imam Husayn (AS), are also included in the Ahl al-Bayt (AS) of the Prophet (SA). Therefore, the "Ahl al-Bayt (AS)" are the fourteen infallible ones. Usually, the "Ahl al-Bayt (AS)" of the Holy Prophet (SA) refer to thirteen persons, who are the offspring of the Holy Prophet (SA).
The Ahl al-Bayt of the Holy Prophet (SA) are endowed with many virtues, excellent qualities, and unchallenging positions, the most important of which are the following two positions:
(1) According to the following Ayah: "..Allah only desires to keep away the uncleanness from you, O Ahl al-Bayt! and to purify you a (thorough) purifying (33:33)."
they have an infallible and purified position; and by virtue of this position, no sin ever touches them.
(2) According to valuable holy "Hadith al-Thaqalayn" of the Prophet (SA), also mentioned earlier, the Ahl al-Bayt (AS) of the Holy Prophet (SA) are inseparable from the Holy Qur'an. There will never be a separation between themselves and the Holy Qur'an. As a result, they commit no error and mistake in perceiving the meaning of the Holy Qur'an.
The prerequisite for possessing these two positions is that the words and deeds of the Ahl al-Bayt of the Holy Prophet (SA) are the criteria and bases (for following) like those of the Holy Prophet (SA) himself. Therefore, the beliefs of Shi'ahs are based on these facts.