Everyone Loves a rebel -- freedom fighter. Or so it seemed at a reception last night at the Saudi Arabian Embassy.

Four Afghan resistance leaders, clothed in their national dress and looking like Old Testament prophets, stood somberly in the embassy foyer as much of official Washington and many in the diplomatic community lavished them with praise.

"We believe in their cause so strongly," said Saudi Ambassador Prince Bandar bin Sultan. "We believe that a show of support for the Afghan cause is most important."

So important is the cause, he added, that "I don't think the Reagan administration has to ask us to do this," as had been widely rumored.

"I think their cause is a just cause," said Secretary of State George Shultz, the most important of many U.S. dignitaries of both political parties who showed up. "We are very supportive. I think it's very gracious that Prince Bandar has hosted sk,1 sw,-1 ld,10 this, and I'm very glad to be associated with him."

Even Mel Levine (D-Calif.), who rallied his House mates against last month's proposed arms sale to Saudi Arabia, made an appearance. "I thought it was an interesting invitation when it came across my desk," he said, adding that despite the lobster and papaya juice, "my vote on the arms sale would be the same."

Support for the Afghan resistance also prompted Levine to accept the invitation. "I think their cause is just, and it's important for them to receive encouragement from us," he said.

Sen. Edward Kennedy (D-Mass.), who helped block the arms sale in the Senate, also made an appearance, clapping former secretary of state Edmund Muskie on the back, posing for pictures while greeting Bandar and the Afghans, and then taking his leave. "They're having a roll call in the Senate, so I have to go back," he explained.

Sen. Gordon Humphrey (R-N.H.) also left the party to vote, but returned for dinner shortly afterward. He's a strong supporter of the United States' withdrawing recognition of the Soviet-backed Afghan government to show support for the resistance. "The first step is to derecognize the puppet government," Humphrey said of possible U.S. efforts to aid the Afghan resistance. "I'm supportive of getting our embassy the hell out of Kabul and kicking the Afghan government out of Washington."

The four resistance leaders are in the process of forming their own government-in-exile, based in Pakistan, and are seeking U.S. recognition of that government as the true representative of the Afghan people. Muskie, for one, was willing to offer his support for the idea. "I think I'd be for it," he said.

The Reagan administration, however, has refused to commit itself on the question.

Although they will not be going home with the official recognition they are seeking, the resistance leaders say the trip has been a success, most notably because of the outpouring of support they have received at gatherings such as this.

"I think this visit is useful for our cause," said Burhanuddin Rabbani, head of the delegation.

Afghan National Liberation Front leader Sibqatallah Mojadedi, who wore a sport coat over his traditional tunic, said the encouragement given by guests at the party was heartening to him. "This may be a sign of official recognition in the future," he said, adding that "we are happy, and the visit was useful to the cause."

Mojadedi nonetheless took exception to press accounts calling the Afghans rebels rather than freedom fighters. "Please don't call us rebels," he said. "We are freedom fighters. We are defending our land."

As they greeted well-wishers, the Afghans looked tired and slightly dazed by the glad-handing style of American politicians, especially Rep. Charles Wilson (D-Tex.), who sat beside Rabbani during dinner and began a lively, Texas-style discourse, pieces of which could be heard two tables away. Rabbani, who does not speak English well, looked confused. While others finished dinner, Mojadedi knelt and prayed, at one point kissing the floor.

For the other guests, who supped on lamb, beef, kibbe, hummus and other delicacies, the party was a Washington-style success.

"I was very pleased by the turnout," said Bandar as he twisted Saudi sabah beads in his hands. "Being a veteran of battles of Congress, it was nice to see Senators Kennedy and Humphrey. We are all big boys, I guess."