Yahrtzeit of Rabbi Yechezkel Landau (1713-1793), a brilliant scholar and leader known popularly by the title of his commentary, Nodeh BiYehuda. Rabbi Landau was born in Poland, and became rabbi of the large and influential community of Prague. He also authored Dagul Mervavah on the Shulchan Aruch and Tzelach on the Talmud. Rabbi Landau interceded with the government on various occasions to counter anti-Semitic measures. In one famous incident, the local bakers of Prague had secretly plotted to poison the bread and sell it only to the Jews. Late one night, there was a knock on Rabbi Landau's door. It was one on the bakers, who decades earlier Rabbi Landau had reached out to help. Out of gratitude, this man revealed the plot, and thousands of Jewish lives were saved.