Muslims in many countries celebrated the first day of Eid al-Adha on September 12, marking the holiday with the slaughter of sheep and other animals. The feast of sacrifice pays tribute to the Prophet Ibrahim (Abraham), who showed his willingness to sacrifice his first son as an act of supplication to God. Families traditionally keep some of the animal's meat for themselves, share some with friends and neighbors, and donate a portion to the needy. While Muslims in Europe, Central Asia, and the Middle East started their celebrations, believers in Pakistan and other countries were still waiting for the holiday to begin one day later.