President Anwar Sadat belittled his Arab critics today and sternly warned against terrorist attacks on Egypt by those who have rejected his peace making with Israel.

Opening a parliamentary debate on ratification of Egypt's peace treaty with Israel, Sadat said:

"I am warning them that Egypt, which is strong and has faith, has the deterrent force. For them to try to kidnap one of our ambassadors or make an incident here or there in a hooligan struggle. . . I would tell them that I am going to retaliate, and very strongly.

"Egypt, which has strength and is very powerful, is able to return a slap, two slaps. We shall return this a hundred and a thousand times stronger."

Sadat was lashing out against threats by his opponents, particularly the Palestine Liberation Organization, to, among other actions, "chop off" his hands, assassinate him and strike against Egyptian targets.

[Apparently carrying out those threats, terrorists exploded bombs at the Israeli Embassy and the Egyptian airline office in Nicosia, Cyprus, and in the Israeli-occupied Arab sector of Jerusalem, wire services reported. The Jerusalem blast wounded 10 Arabs and three Jews, none seriously, and no casualties were reported in the Nicosia explosions.]

In a meandering 2 3/4-hour speech, the Egyptian leader also bore down hard on a relatively small group of internal critics who have vowed to fight ratification of the treaty. He warned them that even though "there will be more democracy and deeper democracy" in Egypt's future, there will be "certain disciplinary measures" as well.

The parliament is expected to debate the treaty for two days, with a ratification deadline set for Monday. Sadat's National Democratic Party controls an easy majority and the pact is expected to get overwhelming approval.

Afterward, Egyptian and Israeli delegates are to meet in the Sinai and exchange the documents, putting them into effect. Sadat and Israeli Prime Minister Menachem Begin then meet May 27 at El Arish, also in the Sinai, where they plan to declare the Egyptian-Israeli border open after 31 years.

U.S. officials in Washington and Israel said Secretary of State Cyrus Vance will join them for the El Arish meeting.

Sadat saved his greatest ire for Iraq, Syria, Jordan and Yasser Arafat's deputy in the Fatah guerrilla organization, Abu Iyad.

Syrian President Hafez Assad and King Hussein of Jordan, he noted, had conducted "blood baths" against the Palestinians, and yet today, quoting an old Arab proverb, he said "the two failures have joined hands" with the Palestinians against Egypt.

Abu Iyad, the Tough guerrilla leader whose real name is Salah Khalaf, was derided as the man who said one bullet would finish Sadat. Sadat added, ironically, that two of Abu Iyad's children attend Egyptian universities, but like 10,000 other Palestinian students, "whom the rejectionist universities would not take," they have nothing to worry about in the way of retaliation.

While his anger with the other Arab nations was clear and explicit, Sadat also held out an olive branch to them.

"They have withdrawn their ambassadors-we just say, 'Godspeed'," he said. "If the ambassadors come back, they are welcome."

In an effort to regain credibility among Arabs who have accused him of acquiescing in continued Israeli occupation of East Jerusalem, he three times repeated, to thunderous applause, "We reject Israeli sovereignty over Arab Jerusalem."

Then, addressing his remarks directly to Palestinians, he said:

"I am inviting them in full sincerity to forget about this bickering and the past. . . Demonstrations do not throw *out the occupations troops. . . Big speeches will not liberate the land. . . A bomb here or there will not liberate the land, and slogans will not make a country. . *. I am telling the Palestinians to take part" CAPTION: Picture, Anwar Sadat opens parliamentary debate on treaty. AP