What kinds of sources and evidence does Ibn Ishaq use to support the statement that his “Sira is the book of the biography of the Messenger of God”?

What kinds of sources and evidence does Ibn Ishaq use to support the statement that his “Sira is the book of the biography of the Messenger of God”? How does Ibn Ishaq employ this material to argue his case that Muhammad is indeed the Messenger of God? be sure to address these questions in both the Meccan and Medinan periods […]