Ali ibn Husayn al-Sajjad (Arabic: ?????? ???? ?????????? ???????????), also known as Zayn al-Abidin (Arabic: ????? ?????????????) (the adornment of the worshippers) and Imam al-Sajjad ("The Prostrating Imam"), was the fourth Shia Imam, after his father Husayn ibn Ali, his uncle Hasan ibn Ali, and his grandfather Ali ibn Abi Talib.
Ali ibn Husayn survived the Battle of Karbala in 680 CE, after which he and other surviving family members and companions of Husayn were taken to Yazid I in Damascus.
Eventually, he was allowed to return to Medina, where he led a secluded life with a few intimate companions.
Imam Sajjad's life and statements were entirely devoted to asceticism and religious teachings, mostly in the form of invocations and supplications.
His famous supplications are known as Al-Sahifa al-Sajjadiyya.