Mohyeldeen Mohammad, who has known ties to the fundamentalist group Profetens Ummah, published the shocking video after sending Abid Raja several hate texts.
In the clip, which was uploaded to Youtube on Tuesday, Mohammad declared his actions were in line with Sharia law.
He claimed Allah would reward him for correcting his enemies.
The extremist said: “When it comes to the text messages mentioned in media the last couple of days, you can make of what you will. But I have only uttered my opinion in regards to Sharia.
“They have mocked my religion, Islam. Therefore I have calm and peace in my heart because I know my intention for what I did.
“I hope Allah will reward me for correcting these enemies of Allah.”
The Profetens Ummah member, who has previously pledged their support to Islamic State and praised Islamic terrorism, added his hatred was fuelled by Mr Raja's comments regarding the niqab and hijab.
Mohammad continued: “First I sent that dog Abid Raja the messages because the blasphemous traitor has mocked Islam and Muslims over a longer period of time. And lately he has mocked the niqab and hijab.” [Daily Express] Read more