There is a saying from Hazrat Hadi (as), which reveals both the knowledgeable and spiritual aspects of Hazrat Abdul-Azim.
An individual once paid a visit to Imam Hadi (as).
Imam (as) asked him: Where are you based?
The man replied: In Rey
Imam Hadi (as) said: "You can ask Abdul-Azim bin 'Abdullah al-Hassani about any issue regarding the religion."
Imam Hadi (as) introduced Abdul-Azim al-Hassani as a Scholar of religion to his Shiites. Then, at the same time, the Imam (as) said: “Send my regards to him.”
This shows the spiritual aspect.
Excerpt from Leader of the Revolution's speech at the holy shrine of Hazrat Abdul-Azim Hassani (as) for the people of Rey (October 27, 1994)
Abdul-Azim was a great person; at the same time, he was a knowledgeable figure and a jihadist whom brought about some interesting initiatives. The late Sheikh Najashi says: "He collected the speeches of Amir al-Mu'minin." Thus, about a hundred and seventy years before Nahj al-Balagheh was published, he collected the speeches of Amir al-Mu'minin; this is very important. It is not unlikely that Sayyid Razi (God bless him) had used his writings.
On the other hand, due to his jihadist character, he secretly fled to Rey. Sheikh Najashi said to escape from the Sultan. He escaped from the Abbasid caliph, from Iraq and Hijaz, and he came to Rey, because the population of Rey was predominantly Shi'ite. In Medina and in Iraq, the same people did not have to escape the caliph. His escape revealed his warrior-like personality. It reveals that he promoted the teachings of Shia Imams, especially during the time of Imam Javad and Imam Hadi (as), since he was, at least, a narrator of these two Imams. It was a strange era: a period of intense repression against the Imams and, at the same time, a period of joy for Shi'ite throughout the Islamic world. This is an important fact that displayed in no other time, during the life of the Imams', did the Shi'ites have so much vitality, dynamism, organization and expansion among the Islamic world as they had during the era of these three Imams (as): Imam Javad, Imam Hadi, and Hazrat Askari (as). Although, these three Imams (as) were under surveillance and extreme pressure in Medina, Baghdad, and Samarra, at that time, one can conclude that he [Abdulazim] was an important and active person who was noticed by the caliph.--He was wanted and thus escaped to Rey.
Therefore, he was a jihadist, a religious scholar, and a scribe of Hadith, he narrated, at the least, from Imam Jawad and Imam Hadi (as).
Statements made during a meeting with organizers of the congress on Hazrat Abdul-Azim al-Hassani (May 26, 2003)