During the Hajj, Muslims remember and commemorate the trials and triumphs of the Prophet Abraham. The Qur'an describes Abraham as follows:
"Surely Abraham was an example, obedient to Allah, by nature upright, and he was not of the polytheists. He was grateful for Our bounties. We chose him and guided him unto a right path. We gave him good in this world, and in the next he will most surely be among the righteous." (Qur'an 16:120-121)
One of Abraham's main trials was to face the command of Allah to kill his only son. Upon hearing this command, he prepared to submit to Allah's will. When he was all prepared to do it, Allah revealed to him that his "sacrifice" had already been fulfilled.