One of the more enduring anti-Semitic myths in Jewish history is the blood libel—the medieval claim that Jews bake their Passover matzo with the blood of gentile children. Perhaps most memorably, the libel was promoted by Osama Hamdan, the official spokesman of Hamas, the designated terrorist group that controls Gaza. The essence of the slander, as by many forms of bigotry, is the recasting of an innocuous Jewish tradition as something sinister. And this past week, just in time for Passover, anti-Israel activists on social media attempted to offer an update to this medieval calumny.It began when Israel’s deputy foreign minister Tzipi Hotovely posted a photo of her department’s annual pre-Passover toast to Twitter. Her Hebrew caption read: “A toast for the [Passover] holiday in the foreign ministry office this morning. Israel has a moral responsibility to act in the diplomatic arena against the atrocities of the Syrian regime.”הרמת כוסית לחג במשרד החוץ הבוקר. לישראל אחריות מוסרית לפעול בזירה הדיפלומטית נגד מעשי הזוועה של המשטר הסורי pic.twitter.com/q9FZ6bME2v\n\n\n\n— Tzipi Hotovely (@TzipiHotovely) April 5, 2017Hotovely thus linked the Jewish history of persecution to the Jewish responsibility to protect others under threat, like the Syrian people. It was a powerful message—and one that that was promptly recast as celebratory revelry for Syrian deaths by anti-Israel propagandists who can’t read Hebrew:Israeli Foreign Ministry officials are literally toasting yesterday’s event in #Syria. I thought they were all shocked and outraged? https://t.co/VLeHcDyAfb\n\n\n\n— Haidar Sumeri (@IraqiSecurity) April 5, 2017This slanderous claim was quickly retweeted and shared by many other prominent anti-Israel users, including Rania Khalek, a far-left writer with 112,000 Twitter followers whose work has appeared in outlets like The Intercept and Electronic Intifada. (Days later, after the deception was exposed by a blogger, she quietly removed her retweet without correction or apology.)As with many anti-Semitic myths, this one soon migrated from one political extreme to the other—in this case, from the far-left to the far-right:Why are Israeli Foreign Ministry officials literally toasting yesterday’s event in Syria? https://t.co/aOwhizFF4j\n\n\n\n— The Hanging Chads (@TheHangingChads) April 6, 2017Why are Jews celebrating a supposed Sarin attack https://t.co/c0QJtF9s3i\n\n\n\n— Zero (@wagecuck) April 6, 2017As by the medieval blood libel, this latest anti-Jewish canard relies on misrepresenting a Passover tradition as murderous to bystanders unfamiliar with Jewish customs. In actuality, it is long-standing Passover practice in Israel to hold pre-holiday toasts for friends, co-workers, and family. Thus, across social media, everyone from Israel’s president to its start-ups posted pictures of their gatherings:#Israel pres. Rivlin raises a toast with soldiers: "#IDF is ready to face any threat from #Syria" pic.twitter.com/FNvfKkBBks\n\n\n\n— Eli Dror (@edrormba) April 12, 2017The Consulate of #Israel ’s team together for a toast before the holidays! #Passover #Easter pic.twitter.com/MLZ8FLQ5ot\n\n\n\n— Israel in Montreal (@IsraelinMTL) April 10, 2017Rooftop toast for #Passover at @MindspaceME @ThinkRiseTLV | #Israel #tech #startup #cowork #Passover2017 pic.twitter.com/BSUNv79Hkx\n\n\n\n— Assaf Luxembourg (@AssafLuxembourg) April 7, 2017It would appear that the mass Jewish celebration of Syrian slaughter is more widespread than even Israel’s worst critics could have imagined.More seriously, this latest blood libel is a reminder, if one was needed, of the enduring nature of anti-Semitic tropes, which somehow find ways to adapt to new mediums and situations without shedding their essential characteristics.