Today is the hillulah of the Ohr HaHayyim haKadosh. R' Hayyim ben Atar. The Chida (R' Hayyim David Azulai) was his student for just one year, but still he called him the teacher from whom he learned everything he knew.
The students of the Baal Shem Tov (who was a contemporary of the Ohr HaHayyim) say that on the day of the death of the Ohr HaHayyim, the Baal Shem Tov informed his students of his passing, even though the Ohr HaHayyim lived in Israel many thousands of miles away. How did he know what transpired? "There is a special secret intention in washing one's hands that is revealed to only one person in the world, and in our time it was revealed to the Ohr Hayyim," He explained, "and today that secret intention (kawannah) was revealed to me." [You can find the story with more detail over at Heichal HaNeginah]
I was blessed this year to make it to his kever motzaei shabbath before the crowds really started to show up.
Today is a powerful day for the Jewish people, a great day to perform mitzwoth and pray. May we all merit to serve HaShem with true intentions today through these challenging times ahead in the merit of the Ohr HaHayyim, the Light of Life.