In a brief emotional ceremony here in Jeddah tonight, the Iranian wife of one of the freed American hostages, John Limbert, untied a tattered yellow ribbon blowing from the flagpole of the U.S. Embassy before flying off to Washington to rejoin her husband.

Embassy officials and families, plus a small group of Saudi employes popping red white and blue ballons, stood by as a smiling and overjoyed Parvaneh Limbert, accompanied by her daughter Mani, 11, and son Shervin, 9, carried out the simple but highly symbolic gesture of hope come true.

"I'm feeling very happy," she told two American reporters, the only outsiders to witness the unusual occasion. "I don't know how to express it."

After the ceremony, given a touch of formality by a spiffy five-man embassy Marine guard, Mrs. Libert hugged and kissed friends goodbye and was toasted with a champagne-like punch on the sandy lawn of the U.S. residence.

Mrs. Limbert said she had already talked for a full hour with her husband in Wiesbaden. "We did not want to put the telephone down," she said.

The American news media had not disclosed their relationship out of respect for the family's anxiety that it might make things more difficult.

Parvaneh waited out the long ordeal of her husband's captivity here in Jeddah, where John had last served before taking up his post as a political officer in Tehran in August 1979. Their many friends here had been of enormous comfort and aid to her during the long months of her wait, she said.

"I had a very bad 14 months since sitting next to the radio and television and asking what was going on," she said reflecting on the months of waiting. "I tried to call friends [in Iran] but unfortunately they had no idea what was happening."

Mrs. Lambert said she met her husband in the late 1960s when he taught at Pahlavi University at Shiraz in southern Iran for four years. Because he is fluent in Persian she had special fears that Iran's revolutionary authorities might single him out for trial as a spy.

Nonetheless, both of them have fond memories of their pre-revoluntionary time in Iran, she said. "It was our best times," she reminisced. "We hope someday we will go back. He loved it very much."