The self-proclaimed mastermind of the Sept. 11, 2001, attacks said Osama bin Laden’s son-in-law, who is on trial in New York on terrorism charges, is “an eloquent, spellbinding speaker” but had no advance knowledge of lethal operations conducted by al-Qaeda.

The unusual submission from Khalid Sheik Mohammed, who is held at Guantanamo Bay, Cuba, was solicited by lawyers for Sulaiman Abu Ghaith, who was captured in 2013 and transferred to New York for prosecution in federal court.

A federal judge allowed Abu Ghaith’s attorneys to submit several hundred questions to Mohammed, whose answers were reviewed by the government before they were returned and filed in federal court in Manhattan.

Everything Mohammed says is presumptively classified, as are the statements of other high-value detainees at Guantanamo Bay.

Abu Ghaith’s attorneys hope to use the 14-page declaration at the trial, which is entering its third week. Prosecutors assert that bin Laden personally recruited Abu Ghaith after the 2001 attacks and used him to attract and motivate new recruits. Abu Ghaith, who is originally from Kuwait, appeared in al-Qaeda propaganda videos that included dire predictions about more attacks using planes.

In one video after the Sept. 11 attacks, Abu Ghaith warned that the “storms shall not stop, especially the airplane storms.” He advised Muslims “not to board any aircraft.”

Prosecutors say those threats were not idle. At the time, al-Qaeda was planning to use shoe bombs to destroy two airliners.

But Mohammed said Abu Ghaith never received military training and did not know any specifics behind the threats he was making.

“I personally never spoke with Sheik Sulaiman Abu Ghaith about the shoe bomb operation,” Mohammed said. “Ghaith was not a military man and had nothing to do with military operations.”

Mohammed added that he never saw Abu Ghaith with Richard Reid, who attempted to blow up a U.S.-bound plane with a bomb hidden in his shoe.

Mohammed also said he didn’t know whether Abu Ghaith swore a loyalty oath to bin Laden. And he said he never saw Abu Ghaith pushing fighters in Afghanistan to take the oath.

Abu Ghaith’s lawyers are hoping to depose Mohammed, but prosecutors oppose any further access.

In the 2006 sentencing phase of the trial of Zacarias Moussaoui, the only Sept. 11 conspirator convicted in federal court, the defense submitted interrogation summaries from Mohammed and other high-value detainees held at secret CIA prisons overseas.

Julie Tate contributed to this report.