The patriarch of monotheism, an arch-prophet (ulu al-azm) called 'Khalilullah,' the friend of God. He is held to be buried, with his wife Sarah and sons Ishaq and Yaqub, in the cave beneath the Ibrahimi Mosque (Cave of Machpelah / Haram al-Khalil) in Hebron (al-Khalil). It is a major ziyaret site sacred to three faiths. (Sources: TDV İslam Ansiklopedisi 'Halil'; en.wikipedia.org/wiki/Cave_of_the_Patriarchs)