Standing as ramrod-straight on the carpet of the Moroccan Embassy as ever on the floor of the Senate, Barry Goldwater delivered in ringing tones the speech he had been warming up to all afternoon.

"I don't give a goddamn what any Russian says about the U.S. Senate," snapped Goldwater, a powerful member of the Senate Armed Forces Committee and unregenerate Cold Warrior.

The more he thought about Soviet Foreign Minister Andrei Gromyko's warnings that Senate alteration could destroy SALT II, the straighter Goldwater's spine grew.

"I think Gromyko killed the SALT treaty. I tried to get the floor today to tell Bobby [Majority Leader Robert C.] Byrd that I had just one message - "Tell that Gromyko to go to hell!'"

As black-tied waiters circulated trays of red caviar, Goldwater evoked the vision of a swirl of filibuster.

"I'll stretch it out as long as I can," he said of the ratification process. "I don't think it's the best Senate I've ever been in, but the last thing anybody likes is being told what to do. That's the best way to make me vote against it.

"Gromyko should have kept his mouth shut," he concluded.

Out in the tented garden, holding the overflow of a HOPE reception, Lt. Gen. William W. Quinn, former Seventh Army commander and deputy director of the Defense Department's Intelligence Agency, took a softer line on Gromyko's comments.

"I surmise that our president told their president that he would have a problem with ratification in the Senate, and Gromyko came out in support of Carter to try to avert the opposition."

Quinn also downplayed the effect of Gromyko's remarks on members of the upper chamber.

"I don't think it's meaningful. Most of the senators know which way they are going to go, and Gromyko won't make that much difference. That," he cautioned, "is a guess."

The occasion of these highly seasoned conversations was a reception honoring the committee of the HOPE Ball, the annual fund-raiser for the international health organization based in Millwood, Va.

HOPE (Health Opportunity for People Everywhere), founded in 1958 by cardiologist William B. Walsh, supplies teachers in medical and health-related fields by invitation to under-developed countries, mostly in Africa and Central and South America.

The ball itself will not be held until Sept. 14, but preparations are well under way. Last year's gala cleared $85,000 for HOPE.

The reception was, in fact, a kind of "business's ball": A number of the guests have been involved in past years with such fund-raisers as the Meridian House Ball, the Heart Ball, the Symphony Ball and the Wolf Trap Ball.

From the haze of conversation, much of it in French, floated the traditional summer topics - boats, Bermuda, congressional recess-and the new Washington buzzwords: subway rides, cab strikes and the joys of a diesel Mercedes-Benz.

Wisest of the guests, perhaps, was Dr. Arthur Burns, a former chairman of the Federal Reserve Board.

"I am the most ignorant man in Washington," he said wryly. "It takes a knowledge or military policy, geophysics and basic science to have an informed judgment on SALT, and I have none of these." CAPTION: Picture, Moroccan Ambassador Ali Bengelloun, far left, with Mrs. Robert F. Foley, chairman of this years's HOPE Ball, and Sen. Barry M. Goldwater; by Harry Naltchayan