Qom Seminary
He was born in a religious family in Khansar City on August 24, 1891 (18th Moharam 1309 AH). He studied Mathematics, Primary Sciences and Seminary lectures in Khansar. To continue his studies he went to Isfahan. His teachers were his great brother "Ayatollah Seyyed Hasan Khansari", Seyyed Mohammad Sadiq Isfahani, Mullah Abdul Karim Gazi, and Mirza Mohammad Ali Toyserkani. He was an expert in medicine, physics, algebra, geometry, astronomy, philosophy, law, metaphysics and metascience. After establishment of Qom Seminary by Ayatollah Haeri, according to his invitation, Haj Seyyed Ahmad Khansari left Isfahan for Qom to teach in the Seminary there. While there, he was considered as a high degree teacher. In Qom Seminary, he taught Theology, Philosophy and Mathematics. Only some of his students, such as Ayatollah Hossein-Ali Montazeri, had the opportunity to learn about explicit sciences mentioned above, and the majority of his students studied jurisprudence in his public lectures. In 1370 AH (Gregorian calendar: October 13, 1950 – October 1, 1951), when Haj Yahya Sajadi died, he went to Tehran according to Ayatollah Boroujerdi's request. In Tehran, he stayed in Sayyed Azizulallah Mosque.