Almost everything Muslims narrate about the Prophet's life comes through the sira of Ibn Ishaq, written in eighth-century Medina and Baghdad. The original does not survive intact; what survives is Ibn Hisham's recension, and Ibn Hisham says openly in his preface that he omitted material — poems he judged spurious, matters that would distress people, and things he found objectionable. Later historians including al-Tabari quote passages from the original that Ibn Hisham dropped, so some of the excisions can be reconstructed. This makes the sira a genuinely interesting document: it is the tradition's primary biography and it comes with its editor's conflict of interest written on the first page. Modern historical-critical scholarship treats it cautiously as a source for the seventh century while acknowledging it is the best one available; Muslim scholarship weighs individual reports by chain quality as it does with hadith. Devotionally, none of this matters much — the sira is read for the character of the man, and it is the source of the stories children learn.