Egyptian students clutched their "Introduction to Farsi" workbooks as they strode to class. Elegant snippets of Persian could be heard in the corridors. The course schedule was taped to a desk: "Elementary Persian," "Modern Iran," "The Ways of Iranians."

This was the Eastern Languages section of Ain Shams University in Cairo, which we visited today for an interview with one of Egypt's leading scholars on Iran. Dr. Mohamed el Said Abdel Mo'men, a professor of Iranian studies, turned out to be an affable, humble academic with amazing stories about his research stint in Iran during the 1970s, when the seeds of dissent were growing into the movement that would culminate with the Islamic revolution of 1979.

The professor, who speaks fluent Persian, claims to have been the first Egyptian to study at an Iranian university during Anwar Sadat's administration. As the sole Arab on an Iranian campus, Abdel Mo'men said, he experienced both the legendary Persian condescension toward their Arab neighbors, as well as the equally legendary Persian hospitality to guests.

Back then, student dissidents who didn't dare confide in fellow Iranians for fear of being sold out to the shah's security forces often showed up at their Egyptian classmate's dorm room, eager to discuss their yearning for political Islam, for revolution, for an end to the decadence that marked the Western-backed shah's regime. The professor said the student activists trusted him, a Sunni, with some of the earliest underground recordings of Ayatollah Khomeini's speeches, as well as banned pamphlets and important Shiite literature.

"Students are always at the core of revolution," Abdel Mo'men said. "When I lived in the dorms in Iran, I would see police and security guards come at dawn and take away groups of students...I think the students trusted me because they knew I wouldn't tell the police. I was a foreigner, and neither a leftist nor an Islamist."

When the unrest increased, Abdel Mo'men said, he was forced to return to Egypt after two years in Tehran. He brought home piles of recordings, documents and literature, which he translated and then wove into one of the Arab world's first books about those heady days: "The Issue of the Iranian Revolution," published in Arabic in 1981.

Abdel Mo'men found that the open gates of learning and cultural exchange had swung shut after the revolution, which sent the shah into exile in Egypt, where he died in 1980. Sadat gave him a state funeral and the shah's tomb is in a Cairo mosque. (At the request of the Egyptian government, Abdel Mo'men had accompanied the shah in Cairo and even translated the deposed ruler's will.)

The professor has visited Iran since it became a Shiite theocracy; all the trips were for official academic conferences. However, with diplomatic relations between Egypt and Iran frozen since just after the revolution, Abdel Mo'men can no longer nurture the close intellectual relationships he once enjoyed with Iranian counterparts.

"I am, after all, Egyptian, and I have to serve my country," the professor said.

As we prepared to leave his office, we asked for contact details for other Egyptian experts on Iran. The professor happily obliged. Then we asked how to get in touch with Iranians living in Cairo, and whether he could arrange meetings for us.

For the first time in our long interview, Abdel Mo'men became visibly uncomfortable and evasive.

"Of course there are Iranians living here," he said, "but we aren't allowed to talk to them."

We told him we could just take the names and track down the Iranians ourselves. The professor continued to shake his head.

"I'm sorry," he said. "I just can't."