Mandatory Credit: Photo by Yousef Masoud/SOPA Images/Shutterstock (12223340f) (EDITORS NOTE: Image contains graphic content) Palestinians slaughter a cow on the first day of Eid al-Adha in the southern Gaza Strip. Eid al-Adha is the holiest festival in Islam, where Muslims slaughter cows and sheep in memory of the Prophet Ibrahim (Ibrahim) for the sacrifice of his son Ismail, as well as go to Mecca to perform the Hajj. Eid al-Adha celebration in Gaza, Palestine - 20 July 2021