The biography of the Messenger of God

The opening sentence of Ibn ‘shag’s Life of Muhammad (Sira) states: “This is the book of the biography of the Messenger of God.” Hence, it is a kind of Muslim gospel whose purpose is to reassure the faithful (as well as to convince the doubters and non-believers) that Muhammad ibn Abd Allah is indeed the Messenger of God. Write a coherent and well-argued essay based on the topic questions below

Be sure to base your essay material from both Ibn Ishaq readings: “The Life of Muhammad–Mecca” and “The Life of Muhammad–Medina”.
What kinds of literary materials does Ibn Ishaq use as evidence to support the statement that his Sira “is the book of the biography of the Messenger of God?” Why does Ibn Ishaq use these types of literary materials specifically? How does Ibn Ishaq employ this literary material to argue his case that Muhammad ibn Abd Allah is indeed the Messenger of God?