"Slaughter and justice cannot dwell together.”

What: Natalie Portman approvingly cited a quotation comparing the way people treat animals to the Holocaust in a video released Monday by the animal rights group PETA. 

​Portman, 37, an Academy Award-winning actress, paid tribute to Nobel laureate Isaac Bashevis Singer and his concern for animal welfare. At one point, she quoted the narrator from Singer's novel "Shosha," saying: "We do to God's creatures what the Nazis did to us."

The video was released to coincide with the 40th anniversary of Singer winning the Nobel Prize in Literature. 

Portman compared Singer's story to her own. She is the descendant of Jews who, like Singer, fled Poland ahead of the Holocaust, which saw the systematic extermination of 6 million Jews. 

“Isaac Singer grew up in the same part of Poland as my family,” Portman said in the video. “And like them, he fled the horrors of the Holocaust. But the cruelties he witnessed made Singer one of the most powerful writers of the 20th century.”

Portman said Singer was "far ahead of his time" in that the characters in his Yiddish novels "championed women's issues, gay marriage, and especially animal rights." She said he “articulated the plight of animals so boldly that the modern world couldn’t ignore him.”

The film clip ends with a final quote from Singer: “As long as people will shed the blood of innocent creatures there can be no peace, no liberty, no harmony. Slaughter and justice cannot dwell together.”

Why: PETA has long courted controversy in its ​advocacy, including when it comes to the Holocaust. 

In 2009, a German court banned PETA from continuing to compare eating meat to the ​Nazi's atrocities against Jews during the HolocaustThe group was forced to stop displaying posters that showed concentration camp inmates, including children, alongside abused animals and slogans like "For animals, all people are Nazis."

Portman's video came at a time when awareness of the Holocaust is said to be ​waning among Americans and ​concerns about anti-Semitism are on the rise.