"Hudud should be enforced on everyone, not just Muslims," said its president Abdullah Zaik Abd Rahman.
"For Muslims, it means cleansing themselves from sin. For non-Muslims, it is for the interest of national security," he told the press at Isma's headquarters here, Friday.
Abdullah Zaik said that the Islamic penal code would safeguard the security and well-being of every citizen in the country.
"They should think ahead and more maturely for the benefit of the Malays and Muslims," he said.
He also said non-Muslims, whom he unapologetically labelled as "immigrants", should know their limits and had no right to question or interfere in the affairs of Muslims.
"The Muslims and the Malays have the right to voice their opinion and to determine the characteristics to mould the future of the nation without being questioned by the immigrants," he said.
When asked if other races did not have the right to speak out, Abdullah Zaik assured that their interests had been well taken care of since the beginning.
"Throughout history, the Muslims and the Malays have safeguarded their interests, so there's no reason why they should worry about anything," he said.
He also said that the "immigrant race" had no right to oppose the shaping of Malaysia into an Islamic country and question the position of the Bumiputera.
"These people, especially the Chinese, have gone overboard meddling in issues concerning Muslims. They should not cross the line," he said.
Abdullah Zaik also lashed out against DAP and described them as "hypocrites" after they lodged a police report against him, urged him to be investigated under the Sedition Act.
"I feel this is an attempt to stop me from being vocal and it is a form of intimidation.
"DAP staunchly opposed the Sedition Act, and now it wants me to be investigated under the Act," he said.
Isma has been under fire for its recent remarks suggesting that Chinese and the British "trespassed" into Tanah Melayu to bully the Malays out of their wealth.
Abdullah Zaik said non-Malays had no right to question national policies.
When asked if the minorities should pay less taxes, he said "they have to pay their taxes. They earn their income from the country, therefore they have to pay."
He also dismissed accusations the group received funding from the Government, saying that the setting up the NGO was on a voluntarily basis.
"That is not correct at all. Isma is not a proxy of the Opposition or the Government. We are just carrying out our duty as Muslims," he said.
He said the Islamist group was fully funded by its own members, which now stand at 20,000 nationwide, including Sabah and Sarawak.