One of those exalted personalities who have had the honour of meeting Imam (as) and having their problems solved by Imam (as) was the great scholar Muqaddas Ardabeli (died 993 A.H.). He was so famous for his piety and worship that whenever a comparison was intended he was mentioned as the ideal example.
It is well-known that whenever Muqaddas Ardabeli came across a difficult question he used to go near the tomb of Ameerul Momineen Ali (as) and seek the solution for the same. Imam Ali (as) used to provide the answer to his question. He had reached such a high position due to his piety and firm belief in Imamat that he was capable of direct communication with Imam Ali (as) One of the students of Muqaddas Ardabeli and a scholar in his own right was aware of his master’s capabilities.
He writes that, one night I was tired due to prolonged study, and in order to refresh myself, I was taking a stroll in the courtyard of the mausoleum of Ameerul Momineen Ali (as). Suddenly, I saw a shadow approaching the tomb although all the doors of the building were locked. Curious to see the outcome of this all, I followed the shadowy figure.
When the figure reached the sanctum all the locks opened automatically and the door swung open as he put his hand on it. He finally stood before the tomb of Imam Ali (as) and saluted. I even heard the reply to his salaam. Then a conversation began in the same voice. Before the conversation could reach to its conclusion, the shadowy figure emerged and began to walk out of the city in the direction of the Kufa mosque. I began to follow him. The person entered the mosque of Kufa and upon reaching the niche he began to converse with someone.
When the conversation ended he came out of the mosque and began to walk back to the city. The whiteness of dawn had begun to spread all over the surroundings. People were slowly arising from their beds and preparing themselves for the morning prayers. As I was following the figure quietly, I could not suppress a sneeze. The person I was following became aware. He turned around and looked at me. When I looked at his face, I saw that he was my teacher, Ayatullah Muqaddas Ardabeli.
I conveyed my salaam to him and confessed that I had been following him all night since he had entered the tomb of Ameerul Momineen (as). I then implored him to tell whom he was conversing within the purified sanctuary and the mosque of Kufa.
Muqaddas Ardabeli first made me promise that I will not divulge this secret during his lifetime. Then he said, My son! Sometimes I find a particular problem difficult to solve. I present it to Ameerul Momeneen Ali Ibn Abi Talib (as) and obtain the solution from him. Last night Ameerul Momineen (as) guided me towards Imam Mahdi (as) and said, My son Mahdi is in the Mosque of Kufa. He is the Imam of your time. Go to him and seek the reply to your question.
I went to the mosque of Kufa as per his orders and found my master Hazrat Mahdi (as) standing in the niche of the mosque. I asked him the questions and received their replies.
This incident is present in many books of Rejal that deal with the biography of Muqaddas Ardabeli. (Those who were successful in the Search for Qaem (as) pages 27-30)