Former President Donald Trump called Vice President Kamala Harris “retarded” at a recent dinner in New York City, where he also railed against Jewish voters supporting her amid the White House race, according to a new report.

Trump made the comments during the event last month at Trump Tower in Manhattan, The New York Times reported Saturday. As the GOP presidential nominee complained about the number of Jewish voters backing his Democratic rival, he reportedly said that they needed their heads examined for not standing with him despite his support for Israel.

Trump has previously sought to put the blame on Jewish voters for a potential election loss this year.

The dinner event, where Trump also suggested that contributors to his campaign needed to do more for him, was attended by high-profile donors including billionaire hedge fund manager Paul Singer. Billionaire investment banker Warren Stephens was present as well, along with former Education Secretary Betsy DeVos and her husband.

The Times, citing seven people with knowledge of the dinner who spoke on the condition of anonymity, said Trump suggested that donors should be grateful to him, with the former president boasting about giving them tax breaks.

The Times’ report comes as Trump has seemed to exhibit increasingly erratic behavior ahead of Election Day. On Thursday, Trump gave a long, rambling speech in Detroit, where he trashed the city he was speaking in, attempted to define the word “grocery” and got defensive about the crowds at his events.

“The whole country’s going to be like — you want to know the truth?” Trump said in Michigan as he discussed a potential Harris win. “It’ll be like Detroit. Our whole country will end up being like Detroit if she’s your president. You’re going to have a mess on your hands.”

On the same day in September when Trump suggested donors should increase their support, Harris was busy holding a campaign event in Los Angeles. She raised $28 million during the event.

Read the full story at The New York Times.