"This is the classic case," said Redskin quarterback Joe Theismann about his receivers, "of hard work paying off."

That hard work, with a group of noname receivers, has produced a 60 percent completion rate, five touchdowns and no interceptions in the last two games.

"Our offense. Where is it? Where is it? People can't ask that anymore," Theismann proclaimed after Sunday's 34-20 scalping of the Dallas Cowboys.

The Redskins have accomplished a superb passing game the last few weeks without the tall, physically overpowering and speed-burning receivers that National Football League fans go gaga watching. These receivers are a laborer's delight.

"It's a little bit different," Coach Jack Pardee said. "We've tried to adopt a system our players can perform in, that our protection can hold up in. It involves a lot of timing and precise routes. Regardless of the size and speed they have there's no reason they can't run precise routes -- run 15 yards deep, for instance, and make their break.

"Then it's up to the quarterback to throw to the guy who should have the best opportunity."

Theismann has been doing that well and using all of his receivers. The Redskins, according to Pardee, call all players in pass routes primary receivers. The numbers speak: in 12 games, only three receivers have caught more than five passes in any one game. In nine games, the Redskins have had at least six receivers catch passes. Eight different players have led the team in receptions in a game this 8-4 season.

"We are a whole group of receivers," Danny Buggs said. Buggs, the team pass-catching leader with 35, said that, "If Lynn Swann were in this organization, he would be the same way," meaning that Swann would merely be one of the group.

Buggs noted that many of the best-known receivers play on teams that throw to the same two or three men most of the time.

Theismann often has said that Redskin passing would improve this season. He cited two reasons: he would get to understand the system better, and so would wide receivers Ricky Thompson and John McDaniel. Thompson and McDaniel were late acquisitions in 1978 and missed training camp.

"It takes belief and understanding both," Theismann said.

That is because the Redskin system involves every potential receiver running full speed on every play, even if the chances are 100 to 1 that the ball will be thrown nowhere near him. The system is predicated on the fact that if every receiver runs his route correctly, the quarterback will perceive the weakest part of the defense and pass accordingly.

"This year I really began to get it down real good," McDaniel said. "I learned the offense last year, but I didn't know the real philosophy about the concept of what we were trying to get done. Since I was in training camp this year, I really began to see and absorb what the offense is about, and it is the training camp that made the difference."

And what is that difference?

"You run routes and maybe sometimes you're not the primary receiver, but you run a route in order to free up another man," McDaniel said. "Sometimes a receiver gets in the mood where if he knows he's not getting the ball, he doesn't care about the detail, which hurts the whole team."

The touchdown McDaniel scored Sunday against Dallas, on a four-yard pass to give the Redskins a 7-0 lead, was a case in point:

McDaniel's job on the play is to run a pass route that controls the free safety inside while Theismann rolls to his left. When no one picked up McDaniel, he continued to run across the middle and became Theismann's target. Six points. The Redskins had the same opportunity against New Orleans but Theismann didn't see McDaniel.

Players complain about drudgery of training camp and all those two-a-day drills, but Thompson admits that is the only way to master the Redskin passing system.

"Sometimes it's hard to make yourself run your pattern the way you're supposed to do it when you know your chances are 90 to 1 the ball's not going to come to you anyway. It's something you have to do over and over and over again, to where no matter what the play called, you're going to run the pattern. And if it's thrown to you when everybody else is covered, you're there, ready to catch the ball."

McDaniel said unabashedly, "We have three of the better wide receivers in the league."

There are also such running backs as Clarence Harmon, John Riggins, Benny Malone and now-injured Buddy Hardeman, plus tight ends Don Warren and Jean Fugett. All have led the team in receptions at least once this season (Buggs is high with three outright game leads and one tie).

"I've never had any doubt in ur receivers," Thompson said. "You know people like to see you go out and throw the ball as far as you can five or six times. You've got to admit, there's not a very good percentage in doing that, although I like to catch the long ball, too.

"But you have to understand, you have to set it up before you can throw it. And we've done a good job of that, taking whatever the defense gives us." i

And then, Theismann releases the bomb.

"Just to loosen them up again," Pardee said.

The Redskins' pass routes are so complex and based on such precise timing that many passes are completed without the receiver seeing the quarterback release the ball.

The Redskins have routes for three-yard, five-yard and seven-yard drops by the quarterback.

"Occasionally I see him release the ball," Thompson said, "But most of the time I don't."

Running back-kick returner Ike Forte remained in traction in Sibley Memorial Hospital yesterday, mainly as a precaution after back spasms Monday. Pardee expects Forte back at Redskin Park today or Thursday and says he should be able to play Sunday against the New York Giants. A back ailment put Forte on injured reserve earlier this season. He came back after clearing waivers and did not count as one of the Redskins' three moves off the injured reserve list . . .

Theismann has thrown 64 straight passes without an interception since the third quarter of the Steelers game . . . The Redskins have not won at the Meadowlands (0-3) since Giants Stadium opened in 1976.