Since the knowledge of Imam Hadi (A.S.) originated from the Prophetic school thus the light of knowledge shone over his heart and made him aware of the secret of creation.
1- One day, the emperor of Rome wrote to one of the caliphs of Bani Abbas, "We have read in Bible that there is one Surah (Chapter) of the heavenly Surahs, which if read by anyone and practiced upon it’s content God will not send that person to the Hell. You write me as to which one is that Surah? Because we did not find it in Bible."
The Abbasade Caliph gathered all the wise men and asked them the question and all of them failed to answer it. The Caliph summoned Imam Hadi (A.S.) and put to him that question Imam (A.S.) opened his lips for the reply and said, "That surah is Surah "Hamd" which every Muslim recites a number of times in his prayers at day and night time."
Then Imam (A.S.) gave some explanations about it, which surprised and astonished all the wise men. The answer of Imam (A.S.) was sent to the emperor of Rome who, having read it, was much pleased and embraced Islam.
2- "Yahya bin Aqsam" who was one of the wise men of Mamoon’s age and the caliphs afterwards asked Imam (A.S.) many questions through a letter which were replied by him. The questions of Yahya and the response given by Imam (A.S.) are as under:
Question No.1. When "Sulayman (A.S.)" demanded the throne of queen "Bilqees" of "Sheba" his minister "Asif Barkhia" said, "I can bring the throne for you in the time of winking of an eye" why did Sulayman (Solomon) (A.S.) himself not do that? Did he himself not have the knowledge?
Answer: Whatever Asif did was through Sulayman (A.S.) and he had received his wisdom and knowledge from him since, Sulayman was a Prophet he had the capacity and power to perform all these works. But because of it, that he wanted to introduce his successor to the people and make them aware of his station he assigned him this work.
Question No.2. On the basis of Quranic version when Yaqoob (Jacob) (A.S.) went to Kanaan along with his sons to see Yousuf (A.S.) all fell down into prostration before Yousuf (Joseph) (A.S.). Why did a Prophet like Yaqoob (A.S.) performed prostration for Yousuf (A.S.). Whereas, prostration is specified only for God?
Answer: This prostration was not for Vousuf (A.S.) but as a thanks giving to God, just like the prostration of the angels for Adam (A.S.) even though, they did not perform it for Adam (A.S.), but prostration to God as a gratitude and thankfulness, regarding this creation, to Him.
Question No.3. Based upon the Quran’s narration, if the edibles and beverages of Paradise are for the sake of pleasure then, why was Adam (A.S.) forbidden to eat the grapes and was expelled from Paradise?
Answer: As God wanted to try and test Adam (A.S.), He commanded him not to obey his wife Hawwa (Eve) (A.S.) and not to eat from that tree. But he opposed it and as a result he was ousted from the haven.
Question No.4. Why did Ali (A.S.) order his men in the battle of Jamal (Camel) to chase and bring into effect the pursuit of only "the warriors" and not to kill those who ran away, or were not armed, or injured? But in the Siffeen battle he ordered to kill them all, whether armed or unarmed, injured or uninjured, whomsoever they found and laid hands upon. Why was this difference in the order?
Answer: Since, the battle of Jamal was a battle of Islam verses Islam and a battle between a deceived Muslim against another Muslim but the battle of Siffeen was a battle of infidels against Islam. It was a combat between Muslim appearing infidels and the real Islam.
The next day Yahyah bin Aksam asked all the wise men present in the assembly of Haroon:
When Adam (A.S.) went to perform Hajj and visit the house of God, who shaved his head off?
All of them were unable to give an answer to him. Then they put question to Imam Hadi (A.S.). He said, "Gabriel the angel of God." Yahyah took pleasure and enjoyed the answers of Imam (A.S.) and admitted to the knowledge station of Imam(A.S.) in the presence of all.