Rep.-elect Alexandria Ocasio-Cortez of New York made a surprise revelation to a progressive Jewish group on the final night of Hannukah on Sunday: She traces her ancestry back to 15th-century Sephardic Jews.

Speaking at an event organized by Jews for Racial and Economic Justice at the Jackson Heights Jewish Center in Queens, the rising Democratic star drew cheers with the revelation, which she told Haaretz was the first time she had spoken publicly about her family's Jewish heritage.

"I knew it! I sensed it!" she said, highlighting a member of the audience who reacted to her revelation.

"One of the things that we discovered about ourselves is that a very very long time ago, generations and generations ago, my family consisted of Sephardic Jews," she said, referring to Jews who are originally from Spain or the Iberian Peninsula. "And ... the story goes that during the Spanish Inquisition, so many people were forced to convert on the exterior to Catholicism, but on the interior, continued to practice their faith, continued to be who they were, even though they were pressured to not be that on the outside world."

Ocasio-Cortez, who made the comments after lighting Hanukkah candles, said some of those practitioners fled Spain, with some landing in Puerto Rico, where she descends from. Ocasio-Cortez added that the lineage showed that "so many of our destinies are tied."

On Monday morning, Ocasio-Cortez posted a series of tweets about her Jewish heritage, responding to coverage of the remarks.

Before everyone jumps one me - yes, culture isn’t DNA.



But to be Puerto Rican is to be the descendant of:

African Moors + slaves,

Taino Indians,

Spanish colonizers,

Jewish refugees,

and likely others.



We are all of these things and something else all at once - we are Boricua. https://t.co/IFC4mwAjor — Alexandria Ocasio-Cortez (@Ocasio2018) December 10, 2018

According to Haaretz, about 300,000 Jews lived in Spain before the Catholic monarchs began the Spanish Inquisition in the late 1400s, in which all Jews and Muslims were ordered to convert to Catholicism or face expulsion or even death. The publication noted that more than 3.5 million Jews are descended from those who fled the country during the inquisition.

The Sunday revelation was not the first time Ocasio-Cortez has discussed her religion. In the Jesuit publication America Magazine, Ocasio-Cortez wrote earlier this year that the ultimate goal of reforming the criminal justice system ties "directly to the heart of our" Catholic faith.

Discussions of reforming our criminal justice system demand us to ask philosophical and moral questions. What should be the ultimate goal of sentencing and incarceration? Is it punishment? Rehabilitation? Forgiveness? For Catholics, these questions tie directly to the heart of our faith.

Ocasio-Cortez, who has become a firebrand on the left after unseating powerful Democratic Rep. Joe Crowley this year, is an outspoken defender of the Palestinian people and has advocated for a two-state solution to the Israel-Palestinian conflict.

A spokesperson for Ocasio-Cortez, 29, did not immediately return a request for comment from NBC News asking how long she has known about her Jewish heritage and how she was made aware of it.