An Ashura for all Muslims
When the Prophet Muhammad and his people moved to Madinah, they found the Jewish tribes there fasted in remembrance of their ancestors being succored from Egypt and Pharaoh -- Yom Kippur, or the Day of Atonement. Muhammad said that Muslims too remember and are grateful for God's blessing on Moses and his people, and so Muslim began fasting on the day of Ashura as well.
A second occasion of remembrance for Muslim is the slaughter of the Prophet's grandson, Hussein, when he challenged the legitimacy of Muawwiya as the fifth caliph of the Muslim world. This is a major holiday for Shi'a Muslims - a day of remembrance and mourning.
Both of these reasons for commemorating Ashura offer us opportunities for reconciliation. Celebrating the blessings of God on Moses and his people brings Jews and Muslims together. Remembering and mourning the murder of the Prophet's grandson, and the tragic devolution of our community into political infighting so very soon after the Prophet's death, can serve as an occasion to bring Sunnis and Shiis together as well.
The common history that Muslims and Jews share can act as a catalyst to discussions on how our two peoples can build a future together -- exploring how we can work together to combat the twin threats of Anti-Semitism and Islamophobia and how we can build bridges in Israel/Palestine to resolve the conflict in that part of the world.
Similarly, all Muslims should mourn the death of the Prophet's grandson in such a horrific manner. By expressing that we too are hurt and outraged at the way he was killed, Sunni Muslims could go a long way to smoothing relations with our Shi'a brethren.