The commonly agreed on belief is the Shi'ite claim that the entombed is Abu Ja'far Muhammad ibn Uthman, the second of the Four Deputies of the 12th Imam.

[3] However, the Sunnis claim that the buried person is the Hadith narrator Ghulam al-Khallal, whose real name is Abu Bakr Abdul Aziz ibn Ja'far, receiving his nickname from his association with the Hanbali jurist Abu Bakr al-Khallal.

[4] Modern historian Imad Abd al-Salam Rauf believes that the mosque contains the grave of Ghulam al-Khallal, stating so in his book Landmarks of Baghdad in the Late Centuries.

[6] After the first World War, condolence gatherings were held in which the preacher talked about the British occupation of Iraq, which led to the worshippers leaving the mosque in a mass march against the occupying forces at the time.

[8] Al-Khilani Mosque was targeted by a suicide terrorist attack in 2007 which resulted in 78 deaths along with 218 injured in the blast.