An email sent to a member of the mosque, seen by the Star, referenced the March 15, 2019 shootings at two Christchurch mosques, which claimed 51 lives.
He reportedly included multiple slurs and threatened to murder every Muslim who "hates the Jewish people".
Local news outlet CP24 reported another message as saying: "We have a right to defend ourselves from the terrorists. The police will take our side. Islam will not defeat us. We have the guns to do a Christchurch all over again in our office."
"We have ... soldiers who have experience as snipers."
The specific mosque has not been named.
"Enough is enough," Farooq later said in a statement.
"While we greatly appreciate the efforts of Toronto Police Service in conducting an investigation into this particular incident, we need action now from the federal government to develop a national action strategy on dismantling xenophobic groups that preach violent ideologies of hate and violence.
"Today, we are dealing with threats to murder members of the Toronto Muslim community en masse. What more needs to happen before action is taken?"
The threats come after 58-year-old volunteer Mohamed-Aslim Zafis was stabbed to death outside the International Muslim Organization (IMO) mosque in Toronto last month.
The "ruthless" prompted in an open letter to Canada Prime Minister Justin Trudeau from the NCCM and 24 other civil liberties and human rights groups, including the World Sikh Organization and the Centre for Israel and Jewish Affairs, calling for an action plan to deal with the growing number of white supremacy groups and neo-Nazi groups in Canada.
"This attack did not happen in isolation," the letter says.
"This attack is one in a long series of a chain of horrifying attacks on racialised communities in Canada. Faith-based communities, as well as racialised communities, have faced attacks on our homes, our places of worship, our children, and our congregants at the hands of white supremacist organizations.
"While we recognise and appreciate that last year, two organisations affiliated with white supremacy were banned under the listing provisions of the Criminal Code, far more needs to be done.
"We look forward to ongoing dialogue with the government to ensure that action be taken now. An attack like this should never happen again."