LEAH RABIN has emerged from a period of mournful bitterness at the assassination of her husband, the warrior-peacemaker Yitzhak Rabin, at the hands of a right-wing religious zealot.

She was smiling and happy at a concert benefit for the Yitzhak Rabin Center for Israel Studies held at Lincoln Center's Avery Fisher Hall on July 15. It was the very night when the newly elected Israeli Prime Minister Ehud Barak was meeting with President Bill Clinton at Camp David to jump-start the stalled peace process.

"Yitzhak did not live to see his dream of peace," the widow intoned. "On the night of Nov. 5, 1995, three bullets put an end to that dream. It was a very long nightmare."

A hot rumor floating in Arab circles may also account for Rabin's cheerful demeanor. Hassan Abu Nimah, Jordan's ambassador to the UN, told me at the reception that he heard that Rabin will be named Israel's ambassador to the UN.

She will ostensibly replace Dore Gold, who was appointed by Benjamin Netanyahu. Gold's two-year contract was extended to August 2000 by the outgoing Foreign Minister Ariel Sharon. But Barak has the option to replace him.

The reception in the promenade, chaired by Irith Federman-Landeau, raised $300,000 for the Rabin Center to be built in Tel Aviv. Among the 200 VIPs on hand were Abu Nimah, Gold, Consul General Shmuel Sisso, ADL counsel Arnold Forster, preeminent jewelry designer Aya Azrielant and husband Ofir, Lifestyles publisher Gabriel Erem and Kenneth Bialkin, president of the American Jewish Historical Society.

The New York Philharmonic, directed by Kurt Mazur, presented the US premiere of composer Dov Seltzer's ambitious Lament for Yitzhak, featuring the Boys Choir of Harlem and the Philadelphia Singers Chorale.

Rabin sat with Henry Kissinger. At times of crescendo, at the sound of gunshots which brought back horrid memories of that traumatic night of her husband's assassination, she lowered her head in her hands.

At intermission she was tête-à-tête with Maurice Tempelsman, the noted diamond dealer who served as companion and personal confidant to Jacqueline Kennedy Onassis in her final years.

Kissinger, who spoke at the reception and again on stage, said, "Yitzhak was my friend, my colleague, sometimes my critic. But we always worked together very closely." When Rabin was ambassador in Washington, the two met almost every week.

"Yitzhak was not really very articulate," Kissinger said. "But he conveyed his commitment and passion when he pursued peace. He gave speeches of biblical quality and became unbelievably eloquent. He said that peace is mentioned 232 times in the Bible. A remarkable man."

Kissinger said he worked with Rabin for 20 years in pursuit of peace. "The dilemma of Israel is how to reconcile peace with security. Rabin realized his profession as a soldier was not enough. He knew he had to find a balance between the security he sought as a soldier and the peace the people yearned for."

The former secretary of state recalled a time when Israeli commando units stormed a place where terrorists had kidnapped a man. Some Israelis were killed, including the son of a man who was killed in the Yom Kippur War of  '73. His mother had forbidden him to join the paratroops where his father was killed. So he joined the special forces. His term was up, but he stayed an extra month and helped in this operation...and was killed.

Someone called Kissinger and said Rabin was deeply depressed and that he should speak to him. Kissinger told Rabin, "Everything you've done has been a preparation for what you are about to do - bring peace to the area."

Rabin said, "We shall see."