Muslims are coming to the end of Eid ul-Adha, also called the Sacrifice Feast, one of the great feasts of the Muslim year. It's interesting from a broader perspective because it is a memorial of what Jews and Christians call the Akedah or Binding of Isaac -- that is, when Abraham took his son to be sacrificed and was stopped by the angel of the Lord. The Koran is slightly ambiguous on whether it was Isaac or Ishmael who was to be sacrificed; it's a very common view among Muslims that it was Ishmael. Given to God as Corban (Qurbani), the son is returned and a sheep is sacrificed as a reminder of God's mercy; Muslims use the day to celebrate God's mercy, to re-dedicate themselves to Him, and to reflect on the preciousness of human life. The standard sort of tradition is to sacrifice an animal, but as this is sometimes impractical, some Muslims in First World nations give the money for their qurbani to poor Muslims abroad. The sheer importance of the occasion -- surpassed only by Eid ul-Fitr, which ends Ramadan -- underlines a point often made, that Islam is in some ways the most Abrahamic of the trio of Judaism, Christianity, and Islam.
Mustafa Akyol has a discussion of conflicts between reformists and traditionalists over the holiday.
And, of course, the occasion naturally brings to mind Kierkegaard's complicated philosophical discussion of the Binding of Isaac in Fear and Trembling.