MINA, Saudi Arabia — Masses of pilgrims on Sunday embarked on a symbolic stoning of the devil in Saudi Arabia under the soaring summer heat. The ritual marks the final days of the Hajj, or Islamic pilgrimage, and the start of the Eid al-Adha celebrations for Muslims around the world.

The stoning is among the final rites of the Hajj, which is one of the Five Pillars of Islam. It came a day after more than 1.8 million pilgrims congregated at a sacred hill, known as Mount Ararat, outside…