Monday, Nov. 3, 2014 was the day of Ashura according to the Hijri calendar. This is a day remembered by all Muslims, Sunni and Shiite, to bear witness to the history of the prophets and mourn the terrible tragedy of Hussein, the grandson of the Prophet Muhammad. It offers lessons for justice, forgiveness and unity for all.Ashura literally means "ten" and corresponds to the 10th day of the lunar month of Muharram, which is also the beginning of the Hijri calendar. Both Jewish and Islamic sources refer to a number of historic events that have taken place on this day. It was on this day that the Prophet Moses saved the Children of Israel from the oppression of Pharaoh, upon which the Jews were asked to fast. After the great flood, Noah's ark landed on the Mount Ararat on this day. According to scripture, Ashura also witnessed the repentance of Adam and David, the birth of Moses and Jesus, the crowning of Solomon and the rescue of Jonah from the belly of the whale.All of these traditions reported in Jewish and Islamic scripture have made Ashura a special day of remembrance, contemplation and gratitude. Jews celebrate it as Yom Kippur, which literally means the "day of atonement." It corresponds to the 10th day of Tishrei, the 7th month in the Jewish calendar when Moses defeated the injustice of Pharaoh, who symbolized all evil and destruction. Like Jews, Muslims celebrate Ashura by fasting, praying and cooking a special sweet dish known in Turkey as ashura. The history of this dish, also known as Noah's Pudding, goes back to the story of Noah when food was scarce and Noah and his companions had to improvise. The result was the mixing of whatever they were able to find - wheat, grains, nuts and dried fruits. Despite the hardships of the journey, their only food turned out to be a sweet one, promising hope and salvation.The day of Ashura is also a day of mourning as it corresponds to the day when Hussein, the grandson of the Prophet Muhammad, and his family members were brutally martyred by the Umayyad Caliph Yazid I in Karbala, in present day Iraq, in year 61 of the Hijri calendar, or 680 A.D. In this ferocious battle, Hussein stood up against oppression, tyranny and injustice and came to symbolize the pinnacle of justice, bravery and nobility. Muslims remember him as the "master of the martyrs" and invoke his courage, rectitude and devotion in the face of oppression and cruelty.The story of Hussein in Karbala is not a Shiite or Sunni story. It is the story of brave souls defending their beliefs and principles in the face of a merciless enemy. It is underlined by devotion and dedication, a noble effort to preserve the heritage of the Prophet and uphold the principle of justice. It is a story that confirms once again that injustice and disunity bring death and destruction. This is a lesson that Muslims of all faiths, sects and inclinations should heed today. Hussein did not die to create more fissures and division among Muslims - he died to preserve the legacy of the Prophet Muhammad. He did not fight as a Sunni or Shiite or Hanafi or Jafari or anything else. He lived and died as a true believer. His courage was not for worldly bravery but an act of submission to God.Today, extremist Sunnis and Shiites are killing each other in the name of religion. They accuse each other of betraying the legacy of the Prophet. They seek to create their little Sunni and Shiite kingdoms to the detriment of their religion and humanity. They hold on to their narrow and sectarian views, not realizing the damage they are causing to their faith and tradition. Instead, they should turn to the example of Hussein and unite against oppression and injustice rather than waste their faith and intelligence on sectarian fighting.Sunni and Shiite scholars, political and religious leaders, experts, tribal chiefs and ordinary people must do everything in their capacity to end this sectarian insanity and reduce tensions that have already claimed thousands of lives in many Muslim countries. The only way to respect and preserve the memory of Hussein is to protect the principles of justice, unity and sincerity for which Hussein gave his life. Ashura also presents an opportunity to improve Jewish-Muslim relations. Yom Kippur in Judaism and Ashura in Islam unite Jews and Muslims against pharaonic oppression and injustice. It celebrates, in humility and devotion, the forgiveness and mercy God has over the children of Adam. It invites us to go beyond religious, ethnic and sectarian differences and remember our humanity and the noble task it places on us all.