President Anwar Sadat of Egypt has offered to Israel a peace that goes far beyond anything any other Arab leader has been willing to propose since the creation of the Jewish state.

Only ten years have passed since the entire Arab world adopted the position on Israel approved by a summit conference in the Sudan - no peace with Israel, no negotiations with Israel, no recognition of Israel. Today, Sadat offered the full, complete peace between Israel and her Arab neighbors that the Israelis have always said they want.

But he did not offer it without conditions. He offered it on terms most Arabs could accept. And there was an immediate deflation of the euphoria that has prevailed here the past few days when Israeli Prime Minister Menahem Begin appeared to rebuff Sadat on all the essential points.

The government is organizing a mass popular welcome for Sadat when he returns to Egypt Monday, but the immediate response to the exchange of speeches between Sadat and Begin in the Israeli Parliament was that Sadat will not be bringing back with him the peace that Egypt wants and needs.

"He got nothing. Begin didn't give him one thing," an Egyptian journalist said. In the words of one intellectual with a sense of history, "the only important thing was that Begin said they have a right to keep the occupied territories. That is what matters."

Reporters who went out to talk to the handful of Egyptians on the streets on this holiday evening said they found disappointment and disillusionment among Egyptians who expected some sign, some gesture from Begin that would encourage Sadat and did not find any.

For nearly a year Sadat has been pursuing a strategy of giving in to the Israelis on all the psychological and perceptual points that would satisfy Israeli hunger for acceptance and recognition, in the hope of persuading Israel to set aside its fear of the Arabs, yield the territories occupied in the 1967 war and agree to the establishment of a Palestinian state.

It was the ultimate extension of that policy for Sadat to go to Jerusalem, stand at attention for the Israeli national anthem, lay a wreath at a memorial to Israeli soldiers who died fighting the Arabs, and then offer them a peace with all the characteristics that Israel has sought for nearly 30 years.

He offered Israel full recognition, full peace, normal relations, a full acceptance of Israel as a partner in the life of the Middle East.

"We welcome you among us," Sadat said in a declaration that few Arabs from any nation have ever made. "We accept to live with you in a lasting and just peace." He offered an end to years of hatred, offered to end Arab attempts to ostracize Israel from the world community.

And he was not talking just about Egypt. According to the English translation of his speech broadcast by Cairo radio, he offered "normal relations among all countries of the region."

While Syria and the Palestine Liberation Organization have opposed Sadat's initiative in going to Israel to ask for peace, the Egyptians have been suggesting that they will use their power as in Sadat's words, "The greatest Arab country," to bring the others along.

In his speech in Jerusalem, Sadat did just what he said before that he was going to do - tell the Israelis that they can have peace but only by accepting the terms set by the Arab summit conference at Rabat in 1973 which included full withdrawal from the territories and recognition of Palestinian rights. The Egyptian strategy has been to take the Israelis at their word when they say that the territories are not the issue, the issue is the grudging nature of the peace that the Arabs have always offered in the past.

Diplomats sympathetic to Egypt appeared crestfallen at the response from Begin. They viewed the Begin speech as a point by point rebuttal of Sadat's offer - a reaffirmation of Israel's claim to the territories, a determination to keep Jerusalem as a "united city," and an attempt to induce the Egyptians to sign a separate peace treaty.

Egyptians were taken aback when Begin said, " We can make the desert fluorish. Let us join hands in this respect." Egyptians resent this Israeli assumption of superior knowhow. Sadat himself called tonight for an end to "obsolete theories or superiority."

Egyptian officials have been warning against overoptimism as a result of the Sadat visit, saying that no matter what the response there would be difficult negotiations before peace could be achieved. But those warnings were largely ignored as Egyptians saw their leader undertake a mission that strained credulity.

But Sadat's immediate problem may be less with the people here at home than with his fellow Arabs, who have been strongly critical of his trip to Israel. He pledged before hand that he would demand from Israel peace terms that the other Arab states could accept, not just something for himself. He did that, but whether the other Arab leaders will be satisfied is not clear.

The wave of protest demonstrations that swept the Arab world yesterday died down but the split between Egypt on one side and Syria and the Palestine Liberation Organization on the other widened.

The executive committee of the PLO today called for a summit conference of the hand line states. Libya, Iraq, South Yemen, Syria and the PLO to "take firm steps against the criminal and impose maximum sanctions and complete isolation of him."

Diplomatic observers here said they considered it significant that the speaker of the Egyptian People's Assembly, Sayed Marei, who is very close to Sadat, anticipated that kind of response and told the assembly, "no Arab has the right to dictate to Egypt the timing for war or for peace."

He added, "the Egyptian people have been suffering for years. They find a million pounds with difficulty while others are enjoying billions as though it was destined that Egypt face difficulties. If Egypt gets rid of its problems, it will enjoy revival." In other words, Sadat is determined to get peace with the Israelis whether the other Arabs like his technique or not.

Thousands of Egyptians prayed in a downtown square at dawn today to show their support for Sadat, who was praying at the same time in the Al Aqsa Mosque in Jerusalem. But the vast majority of the Egyptian people spent a quiet holiday marking the end of the Moslem mouth of the pilgrimage to Mecca.

The Post's special correspondent Joseph Fitchett reported the following from Beirut:

Sadat's Knesset appearance has allayed temporarily the darkest Arab suspicions about his intentions, but not yet reversed Arab governments' hostile attitude toward his lone journey.

The tone of anti-Sadat commentary on Syrian radio and among Palestinians began to shift away from "traitor" towards "dupe." But Arab governments tonight avoided any official position.

Judged by the reactions of Arab viewers - Palestinians, Lebanese and diplomats from other Arab countries - clustered around TV screens here to follow the day's events via broadcasts from Israel, Arab opinion remained ambivalent about Sadat.

Arab viewers here were Impressed by Sadat's performance. His speech put the Arab case along lines accepted to most Arab parties. He made no poltical concessions, notably on the Palestinians and Jerusalem, and showed no interest in the elements of a separate bilateral accord. Yet he seemed to reverse the atmospherics from the last decades three Arab nos" and put the onus on Israel to show more reasonableness, analysts here said.

On the other hand, the same editor was skeptical that Arab governments would be molitied just by Sadat's speech. Even though the Egyptian leader himself defined his goals as a psychological shock to clear procedural logjams on the way to a peace agreement. Many Arabs here felt Sadat's gambit backtired because Israel showed no flexibility in Begin's speech, which was perceived here as nard-nosen.

He has got nothing in exchange for his concession of visiting Israel, particularly at the cost of upsetting other Arab governments by lack of consultations ," a Lebanese analysts said.

A lot of Arab opinion about Sadat's trip, both pro and con, had assumed the Egyptian leader would only run such risks if he had a prior agreement with Israel - an increasingly untenable assumption.

PLO spokesmen her e said today that the lack of Israeli concessions vindicated that PLO view that Sadat's trip was a waste. Syrian radio was echoing the theme.

The PLO call for an Arab "counter summit" to deal with Sadat stands scant chance of materializing, diplomats here said, pointing to the bitter conflict between Syria and Iraq as a major bar to a radical coalition.

Arab reaction, particularly in the crucial countries. Saudi Arabia and Syria , may not crystalize for several days, diplomats said, until after the press conference Monday and Sadat's explanatory speech to his own people following his return to Cairo.