Sadighi made the comments on February 14, the 25th anniversary of Khomeini's fatwa ruling that Rushdie's book "The Satanic Verses" was "blasphemous against Islam" and an Iranian religious foundation offered a bounty for the author's assassination.
The Friday Prayers leader of Sabzevar, Ayatollah Gholam Hossein Ebrahimi, also said that the fatwa remains valid. "This man has committed a horrible crime; he is unforgivable," the cleric was quoted as saying by the hard-line Fars news agency.
The threat to Rushdie's life led to Britain and Iran breaking diplomatic relations in March 1989 and forced Rushdie to live under police protection for several years.
Tehran said it would neither enforce nor hinder the fatwa when it restored ties with London nine years later, maintaining that only Khomeini, who died in 1989, had the power to annul it.
In 2012, the 15 Khordad Foundation that had originally set a bounty on the head of the author in 1989 increased it by $500,000, making the reward $3.3 million.
The move appeared to be linked to protests over an amateurish U.S.-made anti-Islam movie that angered some in Muslim countries.
Rushdie made a first public appearance in 1993 despite the fatwa and has frequently appeared in public since then without incident.