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.

Deutsche Bank was a serious company in business with Donald Trump to make money, defense attorney Jesus Suarez said during his cross examination of former Deutsche Bank executive Nicholas Haigh.

At the height of its relationship with the Trump Organization the company loaned Trump over $378 million, and failed to commission independent appraisals of Trump's properties, Haigh acknowledged. While the bank listed lower estimates for the value of Trump's assets year after year, it continued to do business with Trump and his company.

"We ... the bank hadn't done all the due diligence one would do in the sense of the opinion of value you see in an appraisal," Haigh said, at one point agreeing with the defense's characterization that the bank's internal value services group conducted "sanity checks'' on the numbers.

The direct examination of Haigh by state attorney Kevin Wallace also left a central question about Deutsche Bank's activity unanswered.

In a letter to the court and in previous arguments, lawyers for the attorney general suggested that Haigh might have turned away Trump's business if he had known that Trump's assets were inflated in value.

"As this Court noted during summary judgment arguments, Mr. Haigh testified during OAG's investigation that he may not have authorized lending to the borrower if he had at that time been aware of the inflated asset values contained in Mr. Trump's SFCs [statements of financial condition]," a lawyer for the attorney general wrote to the court in a letter last week.

Wallace never directly posed the hypothetical to Haigh during his direct examination, leaving the question unresolved.

Court subsequently adjourned for the day, with Suarez telling the court he plans to continue his cross examination of Haigh through Thursday afternoon.