President Reagan, fresh from his triumph in the Senate battle to save his sale of radar aircraft to Saudi Arabia, moved quickly to mend his frayed ties with Israel by reassuring the Jewish state of America's commitment to helping it maintain the military and technical advantage on which its security depends.

Administration officials said that immediately after the Senate voted Wednesday to approve the aircraft sale, Reagan sent a message with this pledge to Israeli Prime Minister Menachem Begin and another to Saudi King Khalid stressing the need for U.S.-Saudi cooperation on peace and security in the Middle East.

Reagan's relations with the Begin government had been overtaken by mutual irritation during the intense congressional battle over the Airborne Warning and Control System (AWACS) planes because of Israel's outspoken opposition to the sale. With the sale now assured, administration sources said, Reagan is determined to make clear to the anxious Israelis that they have no reason to fear a lessening of America's three-decade commitment to their security.

The president's message was echoed by several of his top White House aides, including presidential counselor Edwin Meese III, chief of staff James A. Baker III and national security adviser Richard V. Allen.

Meese, speaking to the American Jewish Congress in San Francisco, said: "Our overall relations with Israel are excellent and will continue to improve." Baker, at a White House briefing, stressed that Israel will be kept "qualitatively and quantitatively" ahead of its Arab-world neighbors in military capability, and Allen hinted that equipment provided the Saudis will be balanced by new military aid to Israel.

Speaking on the "Today" show (NBC, WRC), Allen said: "We have no specific plans at present, but you can be sure that since the cooperation between the United States and Israel is reaching new levels, it would over the long run result in additional sales of some type of equipment."

These reassurances won a quick endorsement from the chairman of the Senate Armed Services Committee, John G. Tower (R-Tex.), who predicted that Congress "will be favorably disposed toward supporting whatever military equipment Israel requires to maintain her ability to defend herself and our own interests in the area."

But, despite the White House's deliberate effort to calm Israeli concerns, other administration sources cautioned that the fence-mending campaign is unlikely to mean any major new arms sales to Israel in the immediate future. They noted that since the financially pinched Israeli government cannot afford any major new investments in weaponry, any equipment would have to be an almost outright gift; such a move, they added, would conflict with Reagan's drive for budgetary austerity.

Instead, these sources said, any U.S. efforts to bolster Israeli confidence probably will emphasize increased strategic cooperation measures such as those discussed by Reagan and Begin when the latter visited Washington last month. Lending weight to that idea was a passage in Reagan's message, which was made public by the Israelis and which said:

"The security of Israel remains an essential factor in our decisions on strategic issues in the region. This administration has a continued interest in working with Israel on a wide dimension of strategic issues, efforts which serve our mutual interests."

Reagan also sought yesterday to portray the eight-point plan advanced by Saudi Crown Prince Fahd in August as a potentially important step toward achieving an end to the Arab-Israeli conflict. He said the plan would "recognize Israel as a nation to be negotiated with."

Despite the president's optimistic interpretation, the Saudi plan simply talks of "the right of the people of the region to live in peace." U.S. officials previously have said that the plan, while containing constructive elements, also contains points with which the United States disagrees.

The State Department also announced yesterday that the two AWACS planes sent to Egypt following the murder of President Anwar Sadat will return to their U.S. bases this weekend.

The department also said that Philip C. Habib, the special U.S. envoy who negotiated the cease-fire in Lebanon, will return there around the middle of November for further talks on ending the civil war that has threatened to draw Israel and Syria into conflict within Lebanon.