Islam - The Summit of Religious Evolution — Page 20
20 Pilgrimage to Mecca (Hajj) Hajj must be performed at least once in their lifetime, if economic and political conditions permit. The focal point of this pilgrimage is the remembrance of the great sacrifice of his son Ishmael that Prophet Abraham was prepared to make at God's command. The pilgrims visit Ka'ba, the house of God that Prophet Abraham repaired or built some 4000 years ago.