An Egyptian man sharpens a knife at a shop ahead of the sacrificial Eid al-Adha festival in Cairo on September 23, 2015. Muslims across the world are preparing to celebrate the annual festival of Eid al-Adha, or the Festival of Sacrifice, which marks the end of the Hajj pilgrimage to Mecca and in commemoration of Prophet Abraham's readiness to sacrifice his son to show obedience to God. Photo by Amr Sayed