"We've never asked for any exclusive rights, but we won't accept that we're always being pushed towards the margins of this society," he told the believers who gathered for the prayer in Ljubljana.
Grabus highlighted, among other things, the Constitutional Court's recent upholding of a 2013 law which bans ritual slaughter of animals without prior stunning.
He also noted that the Constitutional Court had refused to decide on a petition to review the law on holidays because it prioritises Christian holidays.
He finally criticized the Human Rights Ombudsman's opinion that male circumcision for non-medical reasons is a violation of children's rights.
"The strange decision of the Constitutional Court regarding holidays and the Human Rights Ombudsman's view on male circumcision as religious tradition in Islam and Judaism bring a message of marginalisation of smaller religious communities, placing the Slovenian legal order among those which fail to respect a large number of its citizens."
The mufti said that Slovenian authorities do not have a clear idea of where in the Slovenian legal and cultural space to place the Islamic community.
He noted that even the totalitarian regime had not banned circumcision, taking days off to celebrate Eid al-Fitr or animal ritual killing on the Kurban Bayram holiday.
"Religious practice is based on millennial tradition and is as such part of Muslim identity," he said, but noted that the community will respect Slovenian law.
"Our activity will remain based on respecting the law, but we'll insist on implementing the rights which enable free practice of our religion, which stems from the Constitution and the freedom of religion act."
Ljubljana Archbishop Stanislav Zore, who heads the Slovenian Bishops' Conference, congratulated Grabus and Muslim believers in Slovenia on the occasion of the holiday.
He said in a written message he hoped the time of fasting and religious festivities following Eid al-Fir will reinforce their efforts for the common good, just society and respect for values.
"Catholics and Muslims share many values which unite us and bring us closer," Zore said, quoting Pope John Paul II as saying in Nigeria in February 1982 that "all, Christians and Muslims, live under the same sun of one and merciful God" and that Christianity and Islam have many things in common, such as the privilege of prayer, duty of justice, respect for human dignity etc.
Eid al-Fitr prayers were also held in another 16 towns across Slovenia. The Ljubljana prayer was held at Tivoli Hall as the Islamic community does not have a mosque yet.
Grabus took this opportunity to thank members of the Islamic community for their help in building the mosque in Ljubljana.
He hopes they will soon be able to announce that stage 2 of the construction of the Islamic Cultural Centre - the mosque's official name - will proceed.
