A clearly divided Israeli Cabinet gave final clearance today for a new settlement near Nablus on the occupied West Bank, the first since the Egyptian-Israeli peace treaty.

Officials of the ultranationalist Gush Eminium, or Faith Block, said they will begin road-building and site clearance this week, perhaps as soon as Monday, and that the first families will move in soon afterward to get the project started.

The Cabinet approval, which came in the form of rejecting an appeal by Deputy Prime Minister Yigael Yadin to reverse an earlier go-ahead, seemed likely to encounter objections from Egypt and the United States as well as Palestinians who live in the area.

Egypt and the United States regard the civilian settlements in territories occupied by Israel since 1967 as being in conflict with international law and particularly inappropriate during the negotiations on West Bank autonomy that began formally a week ago.

[The United States in the past has expressed regret at the Israeli government's settlement policies, citing their effect on peace negotiations. State Department spokesman Ken Brown said yesterday that U.S. policy on the issue remains unchanged, but made no specific comment on the latest Israeli decision.]

Prime Minister Menachem Begin, underlining his determination on the issue, told a meeting of his Herut Party hours after the Cabinet vote: "There has never been an action more legal than settlement by Jews in all the territories of the land of Israel."

The biblical land of Israel, which includes the West Bank, is "holy to the Jewish people, given to it by God and liberated and built by brave men," he said, adding: "Jewish settlement in the land of Isreal is a right and an obligation."

Begin voted for the settlement with a proxy ballot left with Yadin. The prime minister had remained at home during the day writing his keynote speech for the Herut Party convention's opening session.

The Gush Emunim officials said they ultimately plan an urban Jewish center of about 100,000 persons - twice as large as Nablus itself - that will deeply imprint a Jewish presence in the northern hills of the West Bank. Organizers recently have complained , however, that the number of Jews willing to move into the relatively uncomfortable and hostile environment of West Bank settlements is dropping.

Only about 4,000 Israelis have moved in the 48 Jewish settlements on the West Bank. Moshe Merhavia, a Gush Emunim official interviewed by telephone, said nevertheless that his group envisions a city of 100,000 taking form with 10 years. It is to be named Elon Moreh after the first settlement that Abraham built in Samaria when he led the children of Israel to the Promised Land.

Today's decision is certain to generate considerable local opposition since the government plans to confiscate several hundred acres of privately owned Arab land. The government has always maintained that its program of civilian settlement in the West Bank does not require such confiscations, although in the last year numerous sites have been fenced off by order of the military governor for what Arabs regard as the eventual use as civilian outposts.

Today's Cabinet vote reflected deep divisions within the government over the wisdom of starting a new civilian settlement during the negotiations with Egypt on autonomy for the 1.1 million Palestinians in the West Bank and Gaza Strip.

Some ministers also strongly oppose planting Jewish Settlements in any densely populated West Bank region or surrendering to Gush Emunim, which repeatedly has attempted to build illega settlements over government opposition.

The vote was 8-5 in favor of the settlement - or against Yadin's attempt to turn down the outpost. Among those voting against the plan were Defense Minister Ezer Weizman and Foreign Minister Moshe Dayan.

Both have said that pursuing an aggressive settlement policy now will sour the start of the autonomy talks and force Egypt into making settlements a majory issue in the opening round of the deliberations.

Begin voted for the settlement with a proxy ballot left with Yadin. The prime minister had remained at home during the day writing his keynote speech of the Herut Party convention's opening session.

Interior Minister Yosef Burg, chairman of Israel's six-man autonomy negotiating committee, dismissed suggestions that the settlement decision will draw opposition from the United States."I don't see any reason to refer to something decided within the government a couple of hours ago," he said.

Voting against the Nablus settlement - along with Yadin, Dayan and Weizman - were Labor Minister Israel Katz and Justice Minister Shmuel Tumir. Abstaining were Finance Minister Simcha Ehrlich and Commerce Minister Gideon Patt.

Normally, approved of a new settlement is required only by the ministerial defense committee, which last week endorsed the Nablus project. Under the terms of a coalition agreement, however, if any member of the former Democratic Movement for Change Party, which includes Yadin, opposes a proposed settlement, the issue must be decided by the full Cabinet.

The new settlement will be developed by Gush Emunim's Elon Moreh Group, which has been waiting near the former Jordanian Army base at Kadum for permission to move to Rujeib, about three miles south of Nablus in the Samarian hills.

In September, Gush Emunim nearly caused a government crisis by establishing an illegal settlement at the Nablus site, until 150 of its members were forcibly removed by Israeli soldiers. In December, the group again tried too squat on Arab property, but was dispersed by soldiers.

Palestinian residents of Silwan on the southwest edge of Jerusalem charged today that more that 25,000 acres of cultivated land has been taken away from them in the Maale Adummin area between here and Jericho and in the Dead Sea region.

In a letter to Begin, the Silwan residents said that the land is their source of livelihood and they need it to maintain their village economy. They asked Begin to send a copy of their letter to President Carter and Egyptian President Anwar Sadat. CAPTION: Map, no caption, By Dave Cook - The Washington Post