And there was little love for, or faith in, America's new Commander-in-Chief; instead they ripped in to the US for its policies towards Iran, and its role in Syria.
"From the very beginning, America's policies towards Iran have been hostile," a young man wearing a scarf depicting Iran's Supreme Leader Ayatollah Ali Khamenei told CNN.
"It makes no difference which president is in power," he added. "Whoever is in power will have that same outlook on Iran, which is a pity."
The sermon at the Grand Mosalla, a massive complex of religious halls, exhibition areas and sports facilities in central Tehran, was punctuated with the usual chants of "Death to America!" and "Death to Israel!"
But the main topic on the minds of many of those in attendance was the future of the nuclear agreement between Iran, the US and other nations
, aimed at curbing Iran's nuclear ambitions in return for sanctions relief.
Donald Trump has called the agreement a bad deal, and said he wants to renegotiate it.
Iran's government has rejected that idea, and President Hassan Rouhani has insisted that one man cannot repeal the deal
or change its terms
Historically frosty ties
Some of those attending Friday prayers said they believe Trump is bluffing: "This new president Trump, he is making a lot of promises, but I am sure he will not stick with them," said a man who told us he works at Iran's central bank.
Bluffing or not, many in Iran are worried about Trump's tough talk towards the Islamic Republic, and what his new administration will mean for the country.
At a café next door to the University of Tehran, some of those sipping their afternoon tea were highly critical of the new man in the White House.
"He seems like a crazy man, he just seems crazy I think," a young woman said.
Others said the historically frosty ties between the U.S. and Iran had only begun to thaw in the final years of the Obama administration, leaving them wondering whether tensions will ratchet up again under Trump.
"Things were really improving, especially when Hassan Rouhani came to power here," one student told us. "But I feel like it could get worse with Donald [Trump]. Things could get worse again."
"I voted for Hassan Rouhani also because of the nuclear agreement," a physics professor told us. "We need more understanding and diplomacy and less conflict," he added, saying he hoped the new administration in Washington and Tehran could somehow get along.
Iran's leadership seems to be willing to give Donald Trump a chance.
Politicians and analysts argue that anything the incoming US leader said before taking office is likely rhetoric, and that they want to wait and see what the new president does when he assumes power.
"They are not taking it very seriously now," said Mohammad Marandi, Dean of North American Studies at Tehran University, referring to Iranian officials' stance on Trump's earlier comments.
He said some in Iran's leadership believe that Trump, as a businessman, will take a pragmatic approach to US relations with the country, in spite of his tough talk on the campaign trail.
"If Trump ... is serious about doing a deal with Iran, then I think behind the scenes things may happen," Marandi said. "But if the thinks Iran is going to back down or give the United States concessions, he is miscalculating."