The ceremony was a surprise to everyone, especially to the guest of honor. Ron Eliran, the Israeli “Ambassador of Song,” was getting the bar mitzvah that he never had.

He was 90 years old.

The place was a Midtown steakhouse. The Christmas wreath on the wall signaled holiday cheer.

The rabbi was a radio personality.

“I’ve never done a surprise bar mitzvah,” said the rabbi, Joseph Potasnik, one of the hosts on “The Rev and the Rabbi” on WABC radio and executive vice president of the New York Board of Rabbis. He once did a bar mitzvah for an 83-year-old, he said. But 90, never.

The back story was this:

Mr. Eliran, who is a much-traveled singer and bearer of an admirable head of hair, grew up in what was then the British Mandate for Palestine, outside the city of Haifa. As his 13th birthday approached, in 1947, his parents did what parents do.

“They bought the food, they invited like 75 people,” Mr. Eliran’s younger brother, Josh, said. “And then on the day of the bar mitzvah, the British declared a curfew. No one could go out. So we never had a bar mitzvah.”