Israeli Defense Minister Ezer Weizman was everywhere. And to some in the crowd, everything: principal guest but also co-host, politician but also diplomat, warrior but also statesman. And, of course, hero.

"He's been out on the firing line-- he's a hero," said Rep. William Lehman (D-Fla.) over the din of 125 Israeli and American voices Saturday nigth at the Israeli Embassy. "He's got that warrior peronsality that's valid, that gives authenticity."

Described by Lehman, a member of the House Appropriations Committee's subcommittee on foreign operations, as "a helluva good respresentative for the Israeli cause," Weizman has been in town working on two levels-- the legislative and executive.

"When he says he needs something," continued Lehman, "that is the warrior talking and not just a politician."

A bit earlier it had sounded a little like a politician:

"I didnT expect anything substantial-- I didn't ask for anything substantial. What I tried to do," said Weizman of his talks last week with Defense Secretary Harold Brown and Secretary of State Cyrus Vance, "was pave the way for an Israeli-American idscussion and debate in the next few weeks about future weapons."

Now, here was Weizman, the charismatic, ruggedly handsome, sometimes rebellious minister in Isreali Prime Minister Menachem Begin's cabinet, turning on the charm at a weekend social break in those talks that offered yet another "level" of paving the way.

Defense Secretary Brown came; so did President Carter's special Mideast negotiator, Ambassador Robert Strauss. From Capitol Hill were Rep. Sidney Yates (O-Ill.) and Sen. Richard Stone (D-Fla.) who was concerned about a potentially explosive situation in El Salvador. From the Pentagon ("I always feel at home there," said Weizman) was a contingent of brass-without-visible-braid, including Army Chief of Staff Edward C. ("Shy") Meyer. All brought their wives.

As Israeli security guards stood grim-faced out front, Weizman, Israeli Ambassador Ephraim Evron and other Israeli officials milled calmly among their American guests on the back terrace, where violence, much less war, could not have seemed more remote.

Still, that was what Weizman, the warrior, talked about.

"Every time I go with the army I say, Thank God I went to the air force," Weizman, who helped found the Israeli air force and was its first commander, told Meyer. He recounted how as deputy chief of staff in the Israeli Egyptian war in 1967 he toured the Suez Canal at least twice a month. "Once I was caught in one helluva bombardment. I think they realized a senior commander was there. I was absolutely scared. And I said to myself, 'Weizman, you idiot, what are you doing here?'"

"I have a hard time explaining to Harold Brown the difference between the air force and the army," said Meyer, grateful for the judos Weizman handed the army.

"Anything I can do?" Weizman asked, grinning.

Urging Meyer to make an inspection trip to Israel, he reminded him that "now you can even go down to South Lebanon."

If there is peace and quiet there now, Weizman told someone earlier, it is because they go "a good wallop." Politically, "it might be images and television and media," Weizman told Meyer, but only "a good wallop" gets results. Meyer nodded his agreement.

"Our success has always been using a two-by-four even if we didn't need quite that much," said America's No. 1 soldier.

Replied Weizman: "I'm sorry a few civilians were hurt, but if we can have peace and quiet now . . . " His voice trailed off. "Everybody has the safety catches on."

Sometimes he was Weizman, the diplomat.

"I am careful about trying even to understand what goes on internally in the United States. I see Kennedy's face, I see Carter jogging."

"No one understands very much about politics today," said Meyer.

Despite what Weizman called "certain things," he believes Carter to be a president who will go down as "one of the greatest contributors" to Israeli history. He did not wish to "meddle" in speculation over Sen. Edward Kennedy's presidential ambitions-- "I have enough problems at home"-- but President Carter's handling of the Camp David peace talks had been the actions of "a good leader."

"I don't know anyone except President Carter who didn't pack his bag and say 'I'm leaving.'"

Weizman's visit comes on the heels of Israeli requests for economic and military aid for fiscal year 1981 that nearly doubles previous amounts.

The $3.45 billion figure, however, did not shock Rep. Lehman because inflationary aspects as well as additional costs of sophisticated armaments had to be taken into consideration. Nor had he noticed any erosion of support for th: Israelis in the U.S. Congress.

"Whether they're ready to increase the appropriation is difficult to assess," he said.