An established practice from Abraham
Hajj is the pilgrimage to the Sacred Mosque, owed to God by those who are able to make the journey. Its rites are not later inventions, nor are they symbolic ceremonies created after the Quran.
The Quran points back to the origin of these rites, describing Abraham and his son raising the foundations of the House and praying that God accept their work, make them submitters, and show them the rites of worship.
“The people owe it to GOD that they shall observe Hajj to this shrine, when they can afford it.”
Hajj commemorates Abraham's complete submission to God: entering sanctity, circling the Kaaba, moving through the sacred stations, remembering God, and offering sacrifice for the benefit of the poor.