Peola Spurlock said she figured her son was dead. She had received word last Saturday that apparently he had been "martyred" while fighting alongside the Palestine Liberation Organization in Beirut.

Last night, a Washington Post reporter met her as she arrived home from work and told her that her son, Isa Abdullah Ali, formerly Clevin Raphael Holt, was alive and had been interviewed in Beirut earlier in the day by Western correspondents.

"Oh, thank God, thank God," she said, running her hands through her hair and bursting into tears. "Is he really alive?"

Spurlock said she had not heard from him since he left for the Middle East about 1 1/2 years ago.

Abdullah told Post correspondent William Branigan in West Beirut yesterday that he was fighting for the liberation of Palestine, that he had killed a number of Israeli soldiers, and that although he was well, he expected eventually to be killed. He is the first American known to be fighting alongside the PLO.

Last night his mother, who works in the public information office of the Peace Corps, said, "His story is a very, very weird story in American life as far as I'm concerned."

She said he is one of eight children of a particularly close-knit family who dropped out of school in the ninth grade to join the U.S. Army. She described her son as a former choir boy of exceptional intelligence, who had always been fascinated by the military.

He falsified his age and enlisted at the age of 15, leaving a note that read: "Please don't look for me because I know God and I'm taking God with me," Spurlock said. He was discharged from the Army after 18 months and became a Muslim about eight years ago, she said. Since then she has known very little about where he has worked or what he has done.

Abdullah, 25, was quoted yesterday as saying that his life in the United States was behind him and that he had no desire to return. He has a wife, Rimaah, and a 2-year-old child, named Alma-Maya, here and was to have sent for them, but decided not to because of the fighting in Lebanon, Spurlock said.

Of his grown brothers and sisters, one is an accountant, one is in law school, one is a secretary and another is a premedical student, she said.

Last night Spurlock and her children were scanning the television set, looking for possible pictures of her son. "I just wonder where I could have done something differently," she said.