(CNN) -- The man who pleaded guilty in the failed Times Square car bombing said before the incident that the strike would be a "revenge attack," according to an airing Wednesday on an Arabic-language TV network.

Al Arabiya showed what it said was a tape of Pakistani-American Faisal Shahzad, who pleaded guilty in June to the attempt.

The authenticity of the tape could not immediately be verified, and the person in the video appeared sometime before the May 1 event. The comments, made in English, were translated into Arabic for the news report.

He said the "revenge attack" will be carried out "in the name of all the mujahedeen, the fighters and the weak and the oppressed Muslims," he said, mentioning Baitullah Mehsud and Abu Musab al-Zarqawi, and Muslims and Arabs who have been martyred.

"I will take revenge on their behalf, inshallah, and I really wish that the hearts of the Muslims will be pleased with this attack inshallah."

Mehsud was the leader of the Pakistani Taliban, and al-Zarqawi headed al Qaeda in Iraq.

"Eight years have passed with the war in Afghanistan and you will see that the war of the Muslims has just started, and we will show you how Islam will spread throughout the whole world."

The speaker stressed that "jihad" is a prominent pillar of Islam, a term often used to mean "holy war."

"By jihad, Islam is established, Allah's word is made superior," he said. "By abandoning jihad, may Allah protect us from that, Islam is destroyed and Muslims fall into inferior positions. Their honor is lost, their lands are stolen. Their rule and authority vanish. Jihad is an obligated duty in Islam on every Muslim. "

He said Islam will spread across the world. He said democracy will be defeated as communism was.

"All the other -- isms and -- schisms will be defeated and the word of Allah will be supreme, inshallah. And Muslims are gonna do that."