Donald Trump, in New York, had a prep session with his lawyers Sunday ahead his testimony, sources tell ABC News.

Trump's mood during the session fluctuated between fits of anger regarding the case and being "in a good head space," according to sources.

The former president "can be a good witness if he stays focused," one source said.

Former President Trump is due in court to begin his testimony in his $250 million civil fraud trial at 10 a.m. ET.

Hundreds of members of the news media are huddled outside the New York State Supreme Courthouse ahead of Trump's arrival, with some having waited overnight.

After multiple in-court disputes about communications between him and his law clerk, Judge Arthur Engoron modified his limited gag order to cover attorneys in former President Donald Trump's civil fraud trial.

"Defendants may reference my staff as is appropriate to ask about scheduling issues or the management of the trial, which is an integral part of their jobs. What they may not do is to make any further statements about internal and confidential communications (be it conversations, note passing, or anything similar) between me and my staff," Engoron wrote in his supplemental limited gag order on Friday.

Engoron wrote that defense lawyers Chris Kise, Alina Habba, and Clifford Robert made "repeated, inappropriate remarks about my Principal Law Clerk, falsely accusing her of bias against them and of improperly influencing the ongoing bench trial."

The attorneys have raised multiple arguments during the trial that Engoron and his clerk passing notes between each other suggests impropriety and is distracting. Going forward, if the lawyers want to object to communications with his clerk, Engoron advised that they refer to the order as a "blanket statement."

"This gag order is as narrowly tailored as possible to accomplish its purpose, which is to protect the safety of my staff and promote the orderly progression of this trial," Engoron said.

To justify the safety threat, Engoron added that his chambers has received "hundreds of harassing and threatening phone calls, voicemails, emails, letters, and packages" since the start of the trial,

The judge threatened "serious sanctions" for violations of the extended order.

Standing in the courthouse hallway where his father earlier railed against his civil trial, Eric Trump echoed his father's attacks on the New York attorney general and the case levied against his family, following the adjournment of court for the day.

"We have an unbelievable company. We have some of the best assets anywhere in the world. We've never had a default. We've never missed a payment," Eric Trump said of the Trump Organization.

Like his father, he described the case as politically motivated and decried the involvement of his family.

"They've dragged Don and I and Ivanka into it as collateral damage," he said.

Later, addressing reporters on the courthouse steps, he said that the state's efforts should be focused elsewhere.

"Let's get the murderers off the street. Let's take care of the crime. Let's rebuild our infrastructure. Everywhere you drive in New York, you hit a pothole and your car gets destroyed," he said.

Defense attorney Chris Kise began his closing argument by reciting the greatest hits of Trump's defense case, highlighting the lack of victims, intent, and claims of wrongdoing.

According to Kise, Trump's net worth is higher than claimed in his statement of financial condition, and the entire case was "manufactured to pursue a political agenda" by New York Attorney General Letitia James.

"There is no testimony from anyone as to how the defendant's conduct allegedly harmed the marketplace," Kise said with Donald Trump looking on from three feet behind him.

Kise then touted the testimony of the former president, who he praised for "shaping the skyline of New York,'' as evidence that he and his sons committed no wrongdoing.

"There are few people in the world who have succeeded in the real estate industry this well, that have been this successful," Kise said of Trump.

Kise instead placed the blame for the case on Trump's deputies at the Trump Organization and his accountants at Mazars USA.

"President Trump relied on multimillion-dollar accountants at Mazars," Kise said. "Allen Weisselberg, Jeffrey McConney, and Donald Bender were the three most principally involved in the presentation and preparation of the statements of financial condition. Guess which one is a CPA? Bender."