WASHINGTON (CNN) -- Former FBI Director James Comey said Thursday that former Attorney General Loretta Lynch requested he call the Clinton investigation a "matter," partially leading to his decision to make his now-famous statement about the results of that investigation.
Comey said what "capped" his decision to make his public remarks about the conclusion was a publicly reported meeting by Lynch and former President Bill Clinton as their planes were on the same tarmac. He said he decided he had to "protect the credibility of the investigation."
That was public knowledge and drew criticism at the time, but Comey also revealed that Lynch had previously given him instructions on the investigation into the use of a private server by former Secretary of State Hillary Clinton -- which "concerned" him.
"At one point, the attorney general had directed me not to call it an investigation but instead to call it a matter, which confused me and concerned me," Comey said. "That was one of the bricks in the load that led me to conclude I have to step away from the department if we're to close this case credibly."
He later explained that it felt "silly" to not acknowledge the investigation publicly as both presidential campaigns were speaking publicly about it -- but said the Clinton campaign was using "euphemisms" for it, including a "matter."
He said he asked the attorney general, in the likelihood they would both have to testify, if he could confirm there was an investigation.
"I wanted to know, was she going to authorize us to confirm we had an investigation, and she said, 'Yes, but don't call it that, call it a matter,'" Comey said. "And I said, 'Why would I do that?' And she said, 'Just call it a matter.'"
Comey said he didn't push back.
"I said (to myself), 'This isn't a hill worth dying on, OK."
But he said the matter gave him a "queasy feeling."
Comey was testifying Thursday before the Senate intelligence committee on the government's investigation into Russian meddling in the US election and his firing by President Donald Trump.
But he also faced questions about his fateful decision last summer to make public statements on the results of the FBI's investigation into the Clinton server, which were cited by Trump and Justice officials in the first explanation of Comey's firing. Trump later said "this Russia thing" was a factor in his decision to fire Comey.
Comey also called other explanations of his decision to make his conclusions on Clinton public "nonsense" , referencing press reports that a fabricated document -- which he knew to be fake at the time -- influenced his thinking.
Lynch did not respond to a request for comment. A former spokeswoman for Lynch vented her anger on Twitter.
"The irony of him throwing Lynch under the bus but claiming victim with Trump is THICK. He needs to be called on this. #ComeyHearing," Melanie R. Newman tweeted.
Here's a timeline of the roller coaster that is the Trump-Comey relationship:
Comey announces in a news conference that he recommended no charges be filed against Democratic nominee Hillary Clinton, but says her handling of classified information was "extremely careless."
Trump criticizes Comey's announcement at a political rally hours later: "Today is the best evidence ever that we've seen that our system is absolutely, totally rigged. It's rigged."
"He talked about 'extremely careless.' She was 'extremely careless,' " Trump said, echoing Comey's words to describe Clinton's actions. "That's a tremendous word."
Comey announces in a letter to members of Congress that the FBI has discovered emails "that appear pertinent to the investigation" of Clinton's email server.
Trump pounces: "What happened today, starting with the FBI, maybe the system will become a little less rigged. Beautiful."
"I've had a lot of words about the FBI lately, but I give them great credit for having the courage to right this horrible wrong," he added.
Trump praises Comey: "I respect the fact that Director Comey was able to come back after what he did. I respect that very much."
Trump continues to praise Comey's decision to reveal the FBI's review of new emails.
"It took a lot of guts," Trump said. "I really disagreed with him. I was not his fan. But I'll tell you what, what he did, he brought back his reputation. He's got to hang tough, because there's a lot of people want him to do the wrong thing. What he did was the right thing."
The FBI announces that it concluded a review of the newly discovered Clinton emails and that the review found nothing that would change the conclusions of its original investigation into Clinton's use of a private email server.
Trump goes on the attack again: "Hillary Clinton is guilty. She knows it, the FBI knows it, the people know it."
"She is being protected by a rigged system. It's a totally rigged system," he said.
Trump and Comey interact publicly for the first time since Trump's inauguration two days earlier, during an event honoring law enforcement officials at the White House.
"Oh, and there's James, he's become more famous than me," Trump said, singling out Comey before shaking the FBI director's hand and pulling him in for an embrace and a few whispered words.
Comey friend Benjamin Wittes would later explain that Comey had tried to "blend into the background" to avoid a one-on-one interaction with Trump and wanted to avoid "any show of warmth."
"Trump grabs his hand and attempts an embrace. The embrace, however, is entirely one-sided. Comey was disgusted. He regarded the episode as a physical attempt to show closeness and warmth in a fashion calculated to compromise him before Democrats who already mistrusted him," Wittes wrote last month.
January 27 -- The dinner
Trump and Comey break bread together at the White House in what Trump would later describe as one of three times Comey told him he was not the target of the FBI's investigation into potential collusion between Trump campaign associates and Russian officials.
Sources close to Comey also said that Trump asked Comey to pledge his loyalty to him during that dinner.
Trump has denied making that request and those close to Comey have denied he offered any assurances to the President about whether he was under investigation.
And while Trump said he believed Comey "asked for the dinner," former Director of National Intelligence James Clapper said Comey told him Trump had invited him to dinner.
Clapper said Comey was "uneasy with it, both from a standpoint of the optic of compromising his independence and the independence of the FBI."
Wittes, Comey's friend, wrote recently that Comey "did tell me in general terms that early on, Trump had 'asked for loyalty' and that Comey had promised him only honesty. He also told me that Trump was perceptibly uncomfortable with this answer. And he said that ever since, the President had been trying to be chummy in a fashion that Comey felt was designed to absorb him into Trump's world -- to make him part of the team."
February 14 -- The Oval Office meeting
This date is likely to be a major focus of Comey's hearing because it's when -- according to a memo Comey wrote at the time -- Trump asked Comey to drop the federal investigation into his former national security adviser Michael Flynn.
"I hope you can see your way clear to letting this go, to letting Flynn go. He is a good guy. I hope you can let this go," Trump said, according to the Comey memo several of his associates shared with reporters.
Comey only replied: 'I agree he is a good guy," according to the memo.
The White House has only said that the memo did not amount to a "truthful or accurate portrayal of the conversation."
Comey testifies before Congress, confirming that the FBI is investigating "the nature of any links between individuals associated with the Trump campaign and the Russian government and whether there was any coordination between the campaign and Russia's efforts."
He also says he has "no information" to support Trump's recent claim that President Barack Obama ordered his phones tapped during the campaign.
Trump tells Fox Business host Maria Bartiromo that "it's not too late" for him to fire Comey, but says that he has "confidence in him."
"We'll see what happens. You know, it's going to be interesting," he said.
On the eve of Comey's testimony before Congress, Trump tweets: "FBI Director Comey was the best thing that ever happened to Hillary Clinton in that he gave her a free pass for many bad deeds!"
Comey testifies before the Senate Judiciary Committee, but demurs on a slew of questions about the FBI's investigation, particularly in questions about Trump.
"I hope people don't over interpret my answers, but I just don't want to start talking about anything -- what we're looking at and how," Comey says.
Trump fires Comey.
In a letter informing him of his firing, Trump writes that Comey informed him "on three separate occasions that I am not under investigation."
Calling Comey a "showboat" and a "grandstander," Trump says he had decided to fire Comey regardless of the recommendation of Deputy Attorney General Rod Rosenstein.
"When I decided to just do it, I said to myself -- I said, you know, this Russia thing with Trump and Russia is a made-up story," Trump said.
Trump tweets: "James Comey better hope that there are no 'tapes' of our conversations before he starts leaking to the press."
When asked what message he had for Comey ahead of Thursday's hearing, Trump said: "I wish him luck."
See Comey's full remarks about the investigation here.