The fourth infallible apostolic Imam Ali bin Al-Hussein As-Sajjad Zayn-uI 'Abidin (A) - martyred on 25th of Muharram 95 AH in Medina with the poisoning by the then ruler Al-Walid bin Abd-il Malik bin Marwan - was the son of Chief of Martyrs and Master of Youths of Paradise and grandson of holy Prophet (S) Al-Imam Abu Abdellah Al-Hussein bin Ali bin Abi Talib (A) and Shahr Banu, the daughter of King Yazdgerd of Persia.

His epithet was Abu Muhammad and was popularly titled as "Zayn-ul 'Abidin" (adornment of worshippers) and Sayyed-os Sajedin (master of those who prostrate in front of Allah) for his great earnestness in worshipping Allah, the Lord of the Worlds.

Imam spent the first two years of his infancy in the lap of his grandfather Ali bin Abi Talib (A) and then for twelve years he had the gracious patronage of his uncle, the second Holy Imam Al-Hasan Al-Mojtaba (A). In 61 AH when Karbala Tragedy happened, he was present there; and suffered a heartless captivity and imprisonment at the hands of the devilish forces of Yazid.

Imam Zayn-ul 'Abidin (A) was lying semiconscious in his sickbed when Imam Hussein (A) had come for the last time to his camp to bid goodbye to his family.

When the Yazidi army had taken the chaste ladies and children of holy family of Prophet Muhammad (S) as captives, carrying them seated on the bare back of the camels, tied in ropes, this Holy Imam, though sick, was put in heavy tight chains with weighty fixed iron rings round his neck and his ankles, and was made to walk barefooted on the thorny burning plains from Karbala to Kufa and to Syria.

Imam Zayn-ul 'Abidin (A) lived for about thirty-four years after his father. He passed all his life in prayers and supplication to Allah and in remembrance of his martyred father. It is worth noting that his eyes shed blood-tears for 32 years in mourning of Karbala tragedy.

Renowned scholar Allama Majlisi writes, “… Whenever he (Imam Zayn-ul 'Abidin) took water to drink, he wept till the tears filled the pot. Someone talked to him about it and he replied: "Why should not I cry, when my father was denied the water which was free to the beasts and animals?”

He also says, "And never was food brought to him but that he wept, so much so that a servant told him: ‘May I be your ransom, O Son of the Messenger of Allah! I am afraid that you would die (of this weeping).’

It is said that once someone said Imam (A) that you and your forefathers themselves said ‘martyrdom is our inheritance’ then if your father, uncle, brothers and companions of your father were martyred, why you weep so bitterly? Years have gone but you still weep. Imam replied: O man! Martyrdom is our inheritance but, was it also our inheritance that veils of daughters of prophet whom even the sun had not seen were snatched, they were tied in ropes, their tents were torched, they were placed on bare backs of camels, and brought to the bazaars of Syria and Kufa and courts of Yazid and Ibne Zyad??

Whenever Imam (A) was asked about the place of great suffering, he replied ‘Ash-Shaam, Ash-Shaam (Syria, Syria)’.

He was so mindful of Allah that whenever he sat for ablution for prayers, the complexion of his face would change and when he stood at prayer his body was seen trembling. When asked why this was, he replied, "Know ye not before whom I stand in prayer and with whom I hold discourse?"

His charity like his forefathers’ was unassuming and hidden. After his passing away, the people said that hidden charity ended with the departure of this Holy Imam. Like his grandfather Ali bin Abi Talib (A), Imam As-Sajjad (A) used to carry on his own back at night bags of flour and bread for the poor and needy families in Medina.

He was at that time 56 years of age. His Imamate was for thirty-four years and he was laid to rest in the cemetery of Janna-tol Baqee in Medina.

An invaluable collection of his edited prayers are known as As-Sahifah Al-Kamilah or As-Sahifah as-Sajjddiyyah. It is also known as Az-Zabur (Psalm) of Aal Muhammad (A). The collection is an invaluable treasury of wonderfully effective supplications to the Lord in inimitably beautiful language.