It was that the Prophet had defined faith (Iman) as...
It was that the Prophet had defined faith (Iman) as contained in the hearts of men, and that their works (A’amal) confirm it, whereas surrender (Islam) is what tongue expresses which validates the union. (Masudi,Muruj’l Dhahab.V.vii p 382). Although the person of the Imam was not touched by the tyrannical caliphs for a while, they were always suspicions about his activities.
Masudi narrates one such occasion when our Imam was called by Mutawakkil who was not happy about the methods of teachings in the schools in Madina. Mutawakkil asked the Imam a question.
“What does a descendant of your father have to say in regard to Al-Abbas ibn Abdul Muttalib?” Imam answered, “What would a descendant of my father say O’Amir, in regard to a man whose sons required his people to obey, and who expected his sons to obey God.” Caliph was pleased with this reply and let the Imam go.” And in the same connection Masudi quotes another incident, which Ibn Khalikan has incorporated in his description of our 10th Imam ‘Ali Al-Hadi (as) “Secret information had been given to Mutawakkil that the Imam had a quantity of arms, books and other objects for the use of his followers concealed in his house, and being induced by malicious reports he was led to believe that the Imam aspired to the Empire.
Once Mutawakkil sent some soldiers of the Turkish guard to break in on him when he least expected such a visit. They found him quite alone, locked up in his room, clothed in a hair shirt, his head covered with a woolen cloak and his face in the direction of Makka. He was reciting Verses of the Qur’an expressive of God’s promises and threats, and having no other carpet between him and the earth than sand and gravel.
He was carried off in that attire, and brought in the depth of the night, before Mutawakkil. When the caliph asked his captors about the arms and ammunitions found they said, there was nothing in the house which presents a threat to the throne. The caliph was ashamed of his misdeeds and let the Imam go. During the Sixteen years of the Imamate, Imam ‘Ali Naqi (as) had become famous throughout the Islamic world. Those who loved to learn the teachings of Ahlul Bayt always flocked around him.
In the 4th year of Mutawakkil’s reign the Governor of Madina Abdallah ibn Hakim started harassing the Imam. He sent hostile reports against him to Baghdad. He wrote to the Caliph that the Imam was assembling lot of supporters here which could be a danger to the security of the State.