The warning from President Carter to his Cabinet was clear. After I have made a decision, don't pressure me to reverse it.

Carter's ire was aroused by the minirebellion on July 15 against his abortion policy by his own high-level (but sub-Cabinet) female appointees, headed by Midge Costanza, a top White House aide.

Abruptly interrupting the discussion on a distantly related subject during his July 18 Cabinet meeting. Carter suddenly expressed amazement that his own appointees had used his Executive Office Building for their meeting to pressure him on the abortion issue.

Further, he said, if the 40-plus complainants had listened to his campaign statements, they would not be surprised at his proposals to deny federal funding for abortions.

One of those who heard Carter on July 18 got the strong impression he was telling Cabinet members that if ever they felt compelled to battle against major Carter policies they should first resign.

The President's blue eyes were chilly when he described his resentment, an emotion that seemed old considering the background. Costanza discreetly sent her boss a memorandum well before the meeting in the EOB, explaining the revolt. The very next morning, suppressing his true feelings, Carter told Costanza he had read her memo and had dictated some new thoughts for her - but made no objection to the meeting.

Given Carter's insistence that his is "an open administration." his resentment has puzzled the protestors. As Pat Derian, the State Department's humanrights coordinator, who attended the July 15 session, told us: "No one had any interest in embarrassing the President." Likewise, Costanza said to us: "Our meeting was a normal, simple procedure in an open administration to get a message to a man we work for and respect."

Carter did not see it that way, but Costanza can be excused she still does not understand. Her first encounter with the President after the Cabinet meeting came at the State dinner for Italian Premier Giulio Andreotti Tuesday evening. The President was overheard to say only this to her, "Hi, you beautiful woman."

President Carter has yilded to Speaker Thomas P. (Tip) O'Neill's demand that an O'Neill crony from Boston be named to the Federal Election Commission rather than far better qualified candidates.

That gives O'Neill two out of six members on the FEC, whose duties include overseeing campaign contributions to congressional candidates. Although the Supreme Court declared unconstitutional a provision in the election law that gave Congress power to name two commission members, that decision has not stopped the increasingly powerful Speaker.

O'Neill talked President Ford into appointing his pal former Rep. Robert Tiernan of Rhode Island to the commission and then started working on Carter to fill another FEC vacancy with Boston lawyer John McGarry. A close political associte of O'Neill, McGary has been a part-time employee of the House Administration Committee (commuting from Boston for spot assignments dealing with election-campaign disputes).

McGarry seems clearly less qualified than the top candidate for the job, Susan King, an FEC staffer with long experience in campaign finance. But Rep. John Brademas (D-Ind), the House Majority Whip and an O'Neill lieutenant, went to the White House to shoot down King as an overzealous reformer.

Her supporters then turned to Herbert Alexander of Princeton, N.J., long the nation's top campaign finance expert. Such influential backers of King as Senate Majority Whip Alan Cranston (Cal.) switched to Alexander.

But O'Neill insisted on McGarry, who was duly brought in for a chat with the President and received his approval. Cranston quietly bowed to the inevitable.

Presidential aides would rather not talk about whether the President has named the best qualified person. Clearly, Tip O'Neill's Oval Office influece has expanded dramatically since his difficulties six months ago in getting decent inaugural tickets.