Prime Minister Menachem Begin, hailed as a peacemaker and greeted tumultuously by many of his critics in Israel's once-embittered peace movement, came home yesterday to try to put into motion the final steps of his country's first peace with Egypt.

Amid extraordinary security at Ben-Gurion Airport, Begin was welcomed by his Cabinet and scores of members of Parliament before plunging into a crowd of several thousand well-wishers, shaking hands and acknowledging the warm reception with outstretched arms.

In an airport speech, Begin declared, "We bring you from Camp David a peace agreement of security and honor . . . Yes, we really have an agreement and the foundation for peace."

Missing from his remarks was any reference to Jewish civilian settlements on the West Bank of the Jordan River, a topic that caused considerable controversy in Washington before the prime minister's departure, and which dampened the euphoria that followed agreement on a framework for peace reached at the Camp David summit with Egyptian President Anwar Sadat.

"Can we tell you today, citizens of Israel, that we brought peace?" Begin asked rhetorically. "Not yet. We still have to overcome hard days ahead tests and trials and problems.

"But a firm basis has been laid for a peace treaty between us and Egypt, and in its wake between us and other neighbors," Begin said. "Soon, we will be able to sign a peace treaty and to bring the message that not only this generation, but coming generations, too, shall live in our country [with] peace, honor . . ."

Among the most pressing tasks awaiting Begin was a procedural decision on whether to present to the parliament Sadat's demand for dismantlement of Sinai settlements as a package with the Camp David accords, or separately.

Opposition Labor alignment members and factions outside Begin's Likud coalition are insisting - in their own political self-interest - that the settlement issue not be submitted separately, thereby forcing them to share the onus of putting an end to a practice that has deep emotional and religious meaning to many Israelis.

Begin still apparently intends to submit the settlement question independently, thereby casting responsibility for the demise of the civilian outposts beyond his Likud coalition.

Aides to the prime minister say that the issue could be concluded immediately after Monday's scheduled debate, but that a final strategy will be developed in Sunday's Cabinet meeting.

In any case, the prime minister's aides say, they are still confident that up to 100 of the Knesset's 120 members will ratify the Egyptian-Israeli accords even if the issues are submitted separately.

Begin's airport speech sidestepped the parliamentary dispute, which is expected to stir long and acrimonious argument. Begin took a conciliatory tone in which he singled out for praise Israel's schoolteachers, who immediately after the summit ended a week-long strike as a demonstration of national unity. Political observers said Begin probably will make a similar appeal for national unity at the outset of the debate.

"Dear friends, Shabat shalom (peaceful Sabbath) to you and a good and blessed new year to the whole house of Israel - a year of peace," Begin said in a reference to the Jewish new year beginning Oct. 2.

Because his regularly scheduled airline flight was more than an hour late, Begin was forced to cut short the airport reception and hasten to Jerusalem before sundown in observance of the Sabbath.

There, presumably because of approaching nightfall, he was greeted by sparse crowds in streets lined with Israeli flags. Sadat, upon his arrival in November, was hailed by thousands of Israelis in the same streets.

The Jerusalem mayor, Teddy Kollek, greeted Begin with wine and a loaf of bread, following an ancident Jewish custom begun to honor kings returning from success in battle.

The government information center had placed advertisements in yesterday's newspapers urging groups to coordinate arrival demonstrations, although a government spokesman said the purpose was not to create artificial fanfare.

One of the principal organizers of the airport rally was the Peace Now movement, which for seven months has demonstrated against Begin, calling him an obstacle to peace. Most in the crowd were school children brought to the airport by bus.

Some representatives of Jewish settlements in the occupied areas showed up with signs saying, "Any government which demolishes one settlement won't last one single day."

The ultranationalist Gush Emunim sent most of its protestors to a hilltop in the upper Jordan Valley to set up a new "settlement" and said it will continue to erect illegal camps until the Camp David agreements are rejected.

The government, which hesitated for days before dismantling a protest settlement near the West Bank town of Nablus, began dispersing the protest settlers as quickly as they set up camp.