Israeli Prime Minister Menachem Begin said today that he had ordered the Israeli Air Force to destroy the Syrian antiaircraft missiles in Lebanon the day after they were deployed, but that the attack was postponed at the last minute three times that day because of bad weather.

After he recieved an urgent message the next day -- May 1 -- from Secretary of State Alexander M. Haig Jr. asked for time to resolve the crisis through diplomacy, Begin said, he postponed the air strikes again, first for three days and then indefinitely.

Begin's account of the secret air strike orders, given in a speech to parliament, was clearly intended as a warning to Syrian President Hafez Assad to remove the missiles deployed in Lebanon on April 29, the day after Israeli jets shot down two Syrian helicopters, claiming they had been used in an attack on Israeli-supported Christian forces near the Lebanese Christian city of Zahle.

The strongly worded speech also came in the midst of an election campaign in which Begin is fighting hard to preserve power. Last night he told an election rally that if Syria does not remove the missiles, he will order the air force to "act."

Begin urged Assad today to "retreat from the brink" by removing the missiles, but he said Israel can wait only a "relatively short period of time" before taking military action.

Begin's warning came just before he met with special U.S. envoy Philip C. Habib to discuss ways of easing the Syrian missile crisis. Habib arrived today from Damascus, where he met with Assad yesterday.

Habib met with Begin for 1 1/2 hours. He said the talks had been "useful" and were a "kind of opening," but he refused to comment further.

Habib said he reported to Begin to his talks in Beirut and Damascus. The two are to meet again tomorrow and Habib is said to be planning to return to Damascus and, if necessary, conduct extended shuttle diplomacy in an effort to resolve the issue.

Israeli officials said Habib reported no substantial progress in talks with Assad and that the Syrians are still refusing to withdraw the missiles.

After the Habib-Begin meeting, Begin's press secretary, Dan Pattir, said that "both sides agreed that the situation [in Lebanon] should be returned to the status quo," that is, what prevailed before the deployment of the Syrian missiles.

In the speech to parliament, Begin said 14 antiaircraft missiles batteries -- a higher number than the Israeli Army command had given before -- are in Lebanon or along the Syrian-Lebanese border. They include, according to Begin, a battery manned by the Libyan Army.

Begin called the presence of the missiles intolerable but said Israel does not seek a full war with Syria and will give the diplomatic effort a chance. He did not indicate how much time he was willing to give Habib to achieve a negotiate settlement.

Addressing Assad as "enemy speaking to enemy," Begin said: "You want brinkmanship? Withdraw! It will not make you lose any prestige or self-honor. Retreat from the brink. Take out the missiles and take your soldiers and withdraw from Mt. Sanin." He was referring to the Christian forces' redoubt overlooking Zahle, which has been under Syrian attack.

"If, God forbid, this cry will not be answered . . . he who rules Mt. Sanin and the skies of Lebanon will take over all of Lebanon to the Israeli border," Begin said. In that case, he added, "War will be unavoidable under the worst conditions for Israel."

Begin's hour-long speech, which was frequently interrupted by heckling from Communist members of parliament, at times carried conciliatory tones. But it was also laced with frequent warnings to Syria that refusal to withdraw the missiles would bring Israeli military action.

He said he told President Reagan, in response to an appeal May 4, that by postponing military action Israel was assuming "great dangers and risks." But, Begin said, he told Reagan to "try the diplomatic routes."

Begin's extraordinary account of his decision to order air strikes April 30 against the first three Syrian missile batteries in Lebanon caught legislators by surprise and brought criticism from the opposition Labor Party.

Labor Party leader Shimon Peres said, "We are shocked to hear you make it public. Why? Who needs it?"

Former Israeli Army chief-to-staff Haim Bar-Lev, the Labor Party candidate for defense minister in the June 30 election, said Begin had "revealed a secret fact of the highest importance in which the enemy can learn our tactics and draw conclusions.

"It is completely unprecedented that anybody will reveal a military action, even if it did not take place, giving the exact time and exact date. This is something that cannot be forgiven," Bar-Lev added.

Begin, who is also defense minister, said that on the morning of April 30, he ordered the Israeli Air Force commander to destroy the missiles at 11 a.m. But at 10:30, Begin said, he was told the mission had been scrubbed because of bad weather.

Twice more that day, at 1 p.m. and 3 p.m., aircraft were scheduled to take off on bombing missions against the missiles, but were postponed at the last moment, Begin said.

Then, Begin said, he received the message from Haig urging Israel to give more time for a diplomatic effort. Begin said he told U.S. Ambassador Samuel Lewis that Israel would wait three days, or up to seven days if the United States received assurances from Syria that the missiles would be removed. Reagan's message followed, Begin said, and the decision was made by senior cabinet ministers to postpone military action indefinitely.