When White House press secretary Sean Spicer shocked listeners by saying that Hitler “was not using the gas on his own people in the same way that Assad is doing” when he murdered millions of Jews, some of the nation’s most prominent fighters of anti-Semitism didn’t even know about it. It was the first day of Passover — and as part of observing the Jewish holiday, many staff members at the Anti-Defamation League had their phones and televisions off.

When they turned them back on again Wednesday night, they had a surprise waiting for them. While they had been off the Internet, celebrating the Jewish exodus from Egypt in the time of the Pharaoh, Spicer had said in a press briefing that Syrian President Bashar al-Assad’s actions were worse than Hitler’s, though Hitler took Jews to “the Holocaust centers.”

Spicer has apologized. Now, the ADL said Thursday, it’s time for him to brush up on his history.

So the organization wrote him a letter: “While you have apologized,” it said, “this week’s incident as well as others (notably, the International Holocaust Remembrance Day statement omitting Jews and your vociferous defense of it), have exposed a serious gap in your knowledge of the Holocaust, its impact, and the lessons we can learn from it.”

Holocaust education is one of the core activities of the ADL, which also works with law enforcement and companies like Facebook and Google to crack down on modern-day hate groups. The organization has taught classes on Hitler’s murderous campaign — which exterminated 6 million Jews and millions more LGBT people, Poles, socialists and others — to more than 130,000 law enforcement professionals and 35,000 teachers, it said.

It’s prepared to teach the same class to Spicer.

“ADL would be happy to conduct one of these trainings at your convenience for you, your staff, and anyone at the White House who may need to learn more about the Holocaust,” the letter said. “We know you are very busy, but we believe a few hours learning this history will help you understand where you went wrong and prevent you from making these mistakes in the future.”

Spicer did not immediately respond to an email from The Washington Post asking whether he would take the ADL up on the offer. When he apologized for his remarks and CNN host Wolf Blitzer asked if Spicer knew that the Nazis killed millions in gas chambers, Spicer replied, “Yes, clearly I am aware of that.”

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