Ibrahim, the biblical patriarch Abraham, is an important prophet in Islam. He is the son of Azar and the father of Ismail - his first born son - and Is'haq his second born, both of whom are considered Islamic prophets. Ibrahim is considered the Father of the Prophets. Ibrahim is commonly termed Khalil Allah, or "Friend of God" or "Braheem". Islam regards many sorts of the biblical patriarchs as prophets of God. Because of their mutual veneration for Abraham, Islam, Christianity and Judaism are sometimes summarized under the term "Abrahamic religions". The faith of Abraham is called Millat Ibrahim in the Qur'an. Muslims believe that Abraham is a prophet of God, in accordance with the narrative of his life in the Qur'an. Abraham and his son Ishmail are said to have fixed the Kaaba in Mecca. Abraham also has an important role in one of the Five Pillars of Islam, the Hajj, which is a pilgrimage to the city of Mecca and the Masjid al-Haram. The principal aspect of the Hajj is remembering God's test of Abraham where he was asked to sacrifice his first-born son Ishmael.