A paid FBI informant testified Tuesday that he prodded a would-be bomber to move forward with a 2009 plot to attack synagogues and shoot down military planes by falsely promising to make him "the happiest man on planet Earth."

The informant, Shahed Hussain, testified on cross-examination in federal court in Manhattan that he bought food and paid rent for James Cromitie, accused of being the plot's mastermind, weeks before Cromitie and three other men were arrested in an elaborate sting that the defense argues was entrapment.

The government's star witness was grilled about recorded conversations in which he suggested Cromitie would be rewarded with a BMW luxury car and even his own barbershop once the phony mission was completed. The informant admitted that, while posing as a representative of a Pakistani terrorist organization, he also alluded to a potential $250,000 payday.

"You did this because 10 months into the investigation, (Cromitie) hadn't agreed to do anything, right?" defense attorney Vincent Briccetti asked.

"He never said no," Hussain replied.

Briccetti cited another exchange in which Hussain told Cromitie, "My brothers will make you the happiest man on planet Earth."

"You were talking about money, right?" the lawyer asked.

"And religion — both," Hussain said.

Asked to explain the $250,000, the witness claimed the total was merely a code word for the plot. He insisted the men, as aspiring militants, were doing it for "the cause" — not money.

Cromitie, 43, Onta Williams, 34, David Williams, 29, and Laguerre Payen, 28, have pleaded not guilty to charges of conspiracy to use weapons of mass destruction and conspiracy to acquire and use anti-aircraft missiles to kill U.S. officers and employees.

Prosecutors allege that with Hussain's encouragement Cromitie hatched the scheme to blow up the synagogues in the Bronx with remote-controlled bombs. They say the men also wanted to shoot down planes at the Air National Guard base in Newburgh, N.Y., about 60 miles north of New York City.

Agents say they arrested the men last year after they planted the devices — fakes supplied by the FBI — in the Bronx while under heavy surveillance.

Hussain met Cromitie in 2008 after being sent by the FBI to infiltrate a Newburgh mosque. After that, the 53-year-old Pakistani immigrant helped make hundreds of hours of video and audio tapes, which are the centerpiece of the case.