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.

The second day of testimony from the defense's expert accounting witness prompted an argument between attorneys for the two sides over the basic question of what the case is about -- leading defense lawyers to make their fourth unsuccessful request for a directed verdict to end the trial.

The arguments came toward the end of direct testimony by accounting expert defense Eli Bartov, who asserted the New York attorney general's case lacked merit because there was no evidence of any fraud on Trump's statements of financial condition, and that any errors about the values of Trump's properties were unintentional and therefore immaterial.

When the defense attempted to question Bartov about those values, state attorneys objected -- prompting defense attorney Christopher Kise to leap from his seat.

"If they don't call anyone to dispute our values, how have they proven their case?" Kise said.

Judge Arthur Engoron, in a pretrial ruling, already decided that Trump conducted a decade's worth of business using fraudulent financial statements, and state attorney Kevin Wallace suggested that Bartov's findings do not change those findings.

"You can't use false statements in business. That's what the summary judgment decision is all about. I think it is pretty much what the rest of this case is about," Engoron said in response to Kise's question.

Kise argued that if the attorney general doesn't prove what Trump's asset values should have been, the case is a "completely rudderless ship" that needs to be "moored to some sort of standard."

"You can't just say it's a misstatement because you feel like it," Kise argued.

"The standard is truth," Engoron responded.

The exchange prompted Trump's legal spokesperson, Alina Habba, to make the defense's fourth motion for a directed verdict, arguing that Engoron is "wasting our time" if he won't consider their expert testimony.

"They have not proven their case. They haven't," Habba said in her request for a directed verdict.

"Denied," Engoron said within seconds of the request, without hearing a response from lawyers for the New York attorney general.