In the staid State Department, where reporters normally pursue elusive diplomatic nuances, emotions burst through the aplomb in the press room yesterday.

A glimmer of spring was in the air, the sap was rising, and so were the tensions between reporters and spokesmen that bubble just beneath the surface in all Washington press rooms in all seasons. Yesterday, the decorum was shattered completely in just eight minutes, 12:06 p.m. to 12:14 p.m.

Normally forbearing spokesman Hodding Carter III rang down the curtain precipitately, for the first time in this administration, declaring, "The briefing is over!"

Before the abrupt ending, Carter and an American Jewish reporter had angrily challenged each other's veracity; the Jewish reporter sideswiped a Lebanese reporter who tried to cut in, and a notoriously provocative reporter called another, a serious type, a "pompous ass."

The abrasive sequence began with Joseph Polakoff of the Jewish Telegraphic Agency. He challenged a published denial by spokesman Carter that President Carter and Secretary of State Cyrus R. Vance "pressured" Sen. Hubert H. Humphrey into writing a letter just before his death in which he criticized Israeli Prime Minister Menachem Begin's policy.

Polakoff was referring to a Hodding Carter letter published Tuesday in The Washington Post that denied portions of a Sunday column by George F. Will.

Polakoff asked the spokesman challengingly, ". . . Will you deny that the president of the United States talked to Sen. Humphrey within a week of his death, asking him to write this letter to Begin? And will you deny now - and you didn't mention this in your letter - that Secretary Vance, within about 48 hours of Sen. Humphrey's death, called him and asked him about that letter?"

"I will not deny that they both had knowledge of the letter," responded Carter.

"I am not asking that," Polakoff countered.

Polakoff and Carter sparred through an exchange in which Carter denied that the president or Vance had "dictated" Humphrey's letter, which the spokesman said "was something Sen. Humphrey wanted to do." Polakoff claimed, and Carter disagreed, that Carter was trying to deny that the president and Vance had anything to do with the letter. The reporter said he was trying to determine if the letter was suggested to Sen. Humphrey when he was on his deathbed . . ."

Finally, Carter said, "Joe, the letter was written because Sen. Humphrey wanted to write it. He was interested, as everyone is, in peace in the Middle East."

The usually soft-spoken Carter, grapping these days with a rush of world news and, incidentally, the pangs of quitting smoking, added with unaccustomed severity: "Now quite frankly, there are two things I don't have to do:

"One, I don't have to take that tone of voice. And two, I don't have to take your suggestions that you have some goddamned particular handle on truth, okay?"

Polakoff: "Well now just a minute. Just a minute." He went on to protest that he was not invited to a private high-level briefing last week, perhaps, he said, "because I might supply some antidote to some of the poison that's being spread by the State Department . . . I'll take that up later."

Polakoff, pressed on to ask whether the president or Vance "spoke with Senator Humphrey before that letter was written?" Carter replied that Vance spoke to Humphrey several times at that time because, among other reasons . . . he was an old friend and admirer of the senator . . ."

"I am really not going to carry this conversation any further," Carter said.

From the opposite side of the Middle East tangle, an equally determined Lebanese correspondent, Semaan Semaan of the politically oriented weekly Al-Mostakbal, tried to change the subject.

"We don't need the Lebanese reporters to come in and break in on this," Polakoff told Semaan rebuffingly.

Next up was the Rev. Lester Kinsolving, an Episcopal priest and journalist. He specializes in far-out questions. Fellow reporters have voted him out of the State Department Correspondents Association on grounds that he violated its rules, in a lost attempt to exclude him from briefings.

Kinsolving said he had read that the department was opposing Israeli retaliation for last weekend's massacre, and asked Carter:

". . . Could you tell me if I am correct in my recollection that when the Klan threatened the lives of certain southern editors, at least one of them armed himself and, in the absence of effective law enforcement against the Klan, would have shot any Klanner intruding into his home, or chased him across the river border into Arkansas?"

This was a circuitous allusion to the spokesman's father, Pulitzer prize-winning Hodding Carter, publisher and editor of the Mississippi Delta Democrat-Times. Carter dryly responded, "I am confident that there are undoubtedly editors like that. What I think you are starting with is a different premise, however . . ."

Kinsolving tried from another equally remote premise: "If the Carter administration wants Israel not to retaliate, would it be willing - in the example of President Jefferson, with the Barbary pirates . . ."

The press corps dissolved in laughter.

"The assumption is wrong on what you said," said Bernard Gwertzman, diplomatic correspondent of The New York Times.

". . . I don't need any interruption from the mighty New York Times," shouted Kinsolving.

Next, the transcript accurately records, "[Babble]".

"If I could get the floor," demanded Kinsolving. "This is a waste of time . . .," countered Gwertzman, as his colleagues nodded.

"Don't tell me I am wasting time, you pompous ass." shot back Kinsolving. "Don't interrupt me - I don't interrupt you . . ."

"The briefing is over!" Carter interjected. He walked off the podium shaking his head.

Spokesman and reporters quit the scene to return to the real world, where news of the Israeli retaliation would soon overtake them and their deadlines.