Osama bin Laden’s son-in-law and al-Qaida spokesman said he heard before the Sept. 11 attacks that “something big was going to happen” but didn’t know what it was, an FBI agent testified Thursday.

Sulaiman Abu Ghaith told authorities that when he visited al-Qaida training camps in the summer of 2001, he gleaned something major was in the works but never learned of any specific plan to attack the United States, Agent Michael Butsch testified at Abu Ghaith’s federal trial in New York.

The highest-ranking al-Qaida figure to be tried on U.S. soil since the attacks, Abu Ghaith has pleaded not guilty to conspiring to kill Americans and providing material support to al-Qaida.

Abu Ghaith said he was summoned to bin Laden’s home after the 9/11 attacks unfolded, Butsch said.

“Bin Laden first asked him, ‘Did you see what happened?,’ referring to the attacks. And he said he did, and bin Laden said that he did this operation,” the agent said, recounting statements the government says Abu Ghaith made while being flown to the U.S. on an FBI jet after his capture last year.

Bin Laden then asked Abu Ghaith, a Kuwait-born imam who had agreed that summer to put his rhetorical skills to work for al-Qaida, to give a series of speeches — and even gave him bullet points, Abu Ghaith recalled, according to the FBI agent.

Abu Ghaith went on to make a series of videotaped speeches, the first of them on Sept. 12, with bin Laden and other al-Qaida leaders visible alongside him.

“He said the purpose of these videotapes was for propaganda, to get them out into the media,” Butsch said. In an Oct. 9, 2001, video, for instance, Abu Ghaith threatened that “America must know that the storm of airplanes will not abate, with God’s permission.”

According to the FBI’s account of Abu Ghaith’s statements, he initially went to Afghanistan in June 2001 because he was interested in jihadist movements and soon was invited to meet bin Laden, who had heard a tape of his preaching.

Abu Ghaith said he knew al-Qaida viewed people who didn’t share its beliefs as “infidels,” but he compared the group’s worldview to former President George W. Bush’s declaration that other nations were “either with us or against us” in the war on terrorism.

Bin Laden asked him to give sermons at his family compound and to speak at training camps, explaining that “military hardens the heart.” Abu Ghaith said he talked to the recruits about religion and the importance of their training and defending Islam.

Bin Laden requested he join al-Qaida, which Abu Ghaith declined, but he agreed to help the group as a scholar and orator and became its spokesman.

Abu Ghaith’s defense has noted that he’s not accused of involvement in the Sept. 11 plot and has said that while he’s an ideologue, he’s not a terrorism conspirator. One of his attorneys, Zoe Dolan, pointed out while cross-examining Butsch that his exchange with Abu Ghaith, conducted via an FBI translator, wasn’t recorded or transcribed.

Abu Ghaith’s lawyers have said the 48-year-old married bin Laden’s eldest daughter, Fatima, about five years ago.

Abu Ghaith has said in a sworn statement that he left Afghanistan in 2002 for Iran, where he was arrested and held for years. He said he was heading home to Kuwait to see relatives when his flight landed instead in Amman, Jordan, where he was turned over to American authorities.