Judge Merchan has begun hearing arguments about the admissibility of some defense exhibits, including an email communication between Michael Cohen and his one-time attorney Bob Costello's law partner Jeffrey Citron.

Defense attorney Todd Blanche argued that the exhibit could be used to impeach Cohen's testimony.

Judge Merchan said he will not allow the email into evidence. Prosecutors argued that the email was hearsay and cannot fairly offer a window into Cohen's state of mind.

"There is another layer there of hearsay," Merchan said about the email. "I don't see any probative value for impeachment purposes here at all."

"Good morning Mr. Trump," Judge Juan Merchan said as he gaveled in the proceedings.

"It's become apparent that we are not going to be able to sum up tomorrow," the judge said after taking the bench.

Merchan said it's more likely summations will take place next Tuesday, after procedural matters and the Memorial Day break.

"Either have a long break now or a long break then, and unfortunately the calendar is what it is," the judge said.

Prosecutors have entered the courtroom for Day 19 of the trial.

Trump has arrived with his entourage.

Before entering, the former president addressed reporters but ignored their questions about whether he'll testify in the trial.

Donald Trump's former attorney Michael Cohen returns to the witness stand this morning for the final time before prosecutors rest their case against the former president in his criminal hush money trial.

Prosecutors could rest their case later this morning.

Defense attorneys have not yet declared who they plan to call to testify -- including whether Trump will testify in his own defense.

Cohen, the prosecution's last major witness, is expected to complete his cross-examination by Trump's defense team before lunch.

Proceedings are scheduled to get underway at 8:45 a.m. ET with arguments over the admission of additional exhibits, after which the jury is expected back in court at 9:30 a.m.

On redirect examination, Michael Cohen provided some background on the $30,000 he said he stole from the Trump Organization by overcharging them for work he did with Red Finch -- funds that were paid to him as part of the Stormy Daniels reimbursement payment.

"Red Finch is a technology company that I had asked to assist in a CNBC poll, and the poll was regarding the most famous businessmen in, like, the last century," Cohen said, speaking to the jury. "Mr. Trump's name was on that list and at the beginning of this poll he was polling toward the very bottom. It upset him, so he had me come to his office and he provided me with a sheet of paper."

"I reached out to Red Finch who told me he was able to create an algorithm to ensure that Mr. Trump would rise and rise significantly in this poll. We talked about what number Mr. Trump wanted to finish," Cohen said.

The jury sat in rapt attention as Cohen spoke.

Eventually Trump came in No. 9 but he declined to pay Red Finch because CNBC didn't bother following through with the poll, Cohen said. Cohen ended up paying them -- in a brown paper bag in cash, he said.

"You felt some pressure to make some payment to your friend? Hoffinger asked.

"Yes," Cohen responded.

Asked why he did it, Cohen said, "Well for a long time I had been telling him about the $50,000. ... I was angered because of the reduction in the bonus, and so I just felt it was almost like self help."

"I wasn't going to let him have the benefit this way as well," Cohen said, admitting that it was wrong.