I do not think that Sol Linowitz realizes the extent of disbelief he caused by his article: "Questioning Begin's Credibility" (op-ed, June 16). Linowitz was appointed by President Carter as his special ambassador to help negotiate the details of full autonomy of the Palestinians in the West Bank and Gaza. For Linowitz to be more inclined to believe Israeli Prime Minister Menachem Begin and discount President Carter's recollection, now supported by Cyrus Vance's confirmation in his own book, "Hard Choices," is his own prerogative. His view, according to his column, is that both Carter's and Vance's recollections of the point of putting a freeze on the settlements for the duration of negotiations for the autonomy (to us, clearly three to five years) were the result of "physical and emotional strain," and that in such circumstances it seemed to him that "failure of communication, confusion and even misunderstanding would not be unlikely."

But why should the misunderstanding be of only one issue among all the issues and documents that were negotiated? To drag in the late President Anwar Sadat's name in order to support Begin's argument is unfortunate, because the issue immediately becomes one of U.S. credibility and not a conflict of recollections and misunderstanding.

As far as Egyptians are concerned, not a single member of the U.S. delegation to Camp David has had any doubt about what was discussed, understood or promised there: not Zbigniew Brzezinski, Harold Saunders, William Quandt or any other single member. Their testimonies all are on the record.

Linowitz's reference to the FBIS (Foreign Broadcast Information Service) as a document of the State Department, in which he quotes President Sadat as stating that his understanding was that the freeze was for three months only, is misleading in many ways. FBIS is a translation of what is printed or diffused around the world which, in turn, could be subject to error or misinterpretation. Sadat's remarks, which were quoted out of context in Linowitz's article, were clear. The president had already stated in the same press conference that the Egyptian position is identical to the American position and that the building of settlements is illegal and an obstacle to peace, and it must be frozen, and those existing settlements should not be expanded.

Even if we take FBIS as our source, we shall find on the following day, Sept. 21, 1978, testimony by Moshe Dayan, who was asked: "The prime minister is speaking about three months of freeze and there is a U.S.-Egyptian view of five years of freeze; what is the truth?" Dayan said: "The Egyptians spoke and are speaking not only of the negotiations period but of that period of time of the transition period, that is, of the five years."

Dayan could not have been talking about the Egyptian understanding of five years while Sadat was talking about three months. Had the Israelis understood Sadat to have said this at the time, would they have left it and not used it then, and since, in their own disagreement with Carter?

The fact is that Begin, after the negotiators came down from Camp David and the agreements were signed, changed his mind and refused to sign the commitment he made at Camp David to freeze the settlements for the duration of the transition period. Whatever Carter said, the prime minister was adamant in his new position. Harold Saunders, who as a State Department official had been dispatched to persuade the other Arab leaders to support Camp David, subsequently stated in a panel discussion on Sept. 24, 1982, that the decisive factor "was the Israeli settlement issue. It demonstrated to the Saudis that the U.S. could not enforce the Camp David arrangement with Israel." The result was that the Arabs shied away from Camp David.

Needless to say, it defies logic to freeze the building of the settlements only for the duration of negotiations for a peace treaty between Egypt and Israel, since the issue is not directly connected to that treaty. Freezing the settlements while negotiating the Palestinian issue and the future of the West Bank and Gaza is the only reasonable and acceptable logic.

Linowitz and all U.S. negotiators have come to know intimately the depth of Egyptian chagrin and frustration over the continued Israeli intransigence on the settlements. They have continuously urged the Israelis to freeze the settlements as part of the "confidence-building measures" that Egypt believed essential to coax more Arabs into the talks.

Building more settlements was and still is the principal obstacle to peace. It diminishes hope among Arabs, particularly the Palestinians, to join the negotiations while their land is constantly confiscated by Israel. President Reagan confirmed in his peace initiative of Sept. 1, 1982, that "the immediate adoption of a settlement freeze by Israel more than any other action could create the confidence needed for wider participation in these talks. Further settlement activity is in no way necessary for the security of Israel and only diminishes the confidence of the Arabs that a final outcome can be freely and fairly negotiated."