The chairman of the mosque linked to last week's shooting outside police headquarters in Parramatta has hit out at extremists in the community, saying there is no place for politics in a place of worship.
And in a sermon at Parramatta Mosque on Friday, Neil El-Kadomi will issue an extraordinary challenge to worshippers: "If you don't like Australia, leave."
Mr Kadomi will deliver the sermon to more than 400 people in the same hall where only a week earlier 15-year-old Farhad Jabar cloaked himself in black before walking 500 metres down the road to shoot a NSW police employee in the back of the head. 
He will tell those present that enough is enough. "We will not tolerate anyone who wants to get us into trouble," he said.
Fairfax Media understands that police are close to confirming that a Wentworthville teenager, who cannot be named, was the one who sourced a handgun from a Middle Eastern crime figure and handed it to Jabar in Parramatta Mosque last Friday.
Search warrants have been executed and CCTV footage reviewed. But Mr Kadomi denied the mosque had anything to do with the teenager's spiral into extremism that ended with the death of NSW police finance worker Curtis Cheng.
"Farhad was a real wake-up call," he said. "To anyone who has crime in mind, if you come to this mosque we will tell the police."
The former teacher warned that those who did not respect Australian values would be expelled from the Islamic community in Parramatta.
"We live in this country, you must respect it," he said. "If you don't like it, leave."
Those words could just as easily have come from the leader of the anti-Islamic Party for Freedom, Nick Folkes, who has called on hundreds to protest against the mosque on Friday.
"The high-maintenance Islamic community needs constant monitoring to prevent further terrorist attacks," he said.
Inside the mosque, located behind blue neon lights and a fire escape in an apartment building in the Parramatta CBD, Mr Kadomi will urge worshippers to be on the lookout for radicalisation. "We didn't like to spy, but now the community must be vigilant," he said.
The past week has taken its toll on Mr Kadomi. On Wednesday he lashed out at reporters, kicking at cameramen and telling them to "f--- off".
The stress had got to him, he said. But the pressure has been building for the past 12 months.
NSW police have visited the mosque several times since the Operation Appleby raids in   September last year, after it emerged a number of men arrested were linked to an extremist group of street preachers who prayed there.
Mr Kadomi said that while groups of men had been seen hanging around the mosque, it was not his role to check on every person's political connections.
"If somebody walks into McDonald's and shoots everyone, is McDonald's blamed?" he asked.
Despite feeling under siege, he said that a tiny proportion of the Islamic community had damaged the religion's reputation.
"Ninety-nine per cent of the people in the mosque are good, educated people. We have a few who are giving us a bad name."
To prevent future tragedies he urged parents to be more involved in their children's activities.
"Good kids can become very nasty people," he said, standing under an Islamic verse that warned believers to not be tempted by wrath. "Too many parents say, 'My kids are very good kids,' without checking what they are up to before, during and after school.
"Know what your children are doing," he said.