Not only al-Mutawakkil, but also his successors opposition to the Imam (A.S.) was fierce. After the death of al-Mutawakkil, al-Mustansir, al-Musta`in and al-Mu`tazz carried on the same mission of harassment against the family of the Imam.
Al-Mu`tazz, understanding the uncontrollable and intense devotion of the people towards the Imam, eventually contrived the Imam’s assassination. He got him poisoned through an ambassador that resulted in the Imam’s martyrdom.
The martyrdom occurred on 3rd Rajab 254 AH, and his funeral prayer was conducted by his son, Imam Hasan al-Askari (A.S.). The Imam (A.S.) was only forty-two years old at the time of martyrdom. The period of his Imamate was thirty-five years . He was buried in Sammarra Iraq.
Regarding Imam Hadi’s (as) worship of God, it has been said that:
His extreme enthusiasm for worshipping God made him restless at nights. He slept a bit and then woke up for worship of God.
Imam Hadi recited the holy Quran so beautifully that anyone who heard his voice broke into tears.
He was patient to the extent that after realizing that a person named Boraiheh had backbitten him to Mutawakkil, he patiently forgave him.
Regarding scientific and theoretical issues, Imam Hadi elaborated on the viewpoints of Islam and responded to ambiguities.
The Imam empowered the insight and thinking of his companions and guided them to the right direction. He also guided the people’s struggles and met their needs.