Al-Sahifa al-Sajjadiyya is a collection of supplications and whispered prayers composed by Imam Sajjad (as), the great-grandson of the Islamic Prophet Muhammad pbuh. The title "al-Sahifa al-Sajjadiyya" means "the book of Sajjad", Sajjad being the epithet of Ali ibn Husayn (as), the fourth Imam.
Al-Sahifa al-Sajjadiyya has several titles, such as "Sister of the Quran", "Gospel of the Holy Household" and "Psalms of the Muhammad dynasty", names which clearly indicate the importance of the book for Shia Islam. In the form of supplication, it expresses Islamic knowledge and thought and involves all aspects of individual, social, economical, political and cultural life. Reason, human feelings, emotions and conscience are all addressed by it.