History writing in Islam’s classical period (2nd-4th/8th-10th centuries) was built from quoted discourse. The raw materials of most surviving texts were short narratives (akhbar), often transmitted from earlier sources. The quotation of treaties, wills, letters, speeches and even conversations was also integral to Islamic historiography’s structure. But where did all these documentary quotations originate? Modern scholars tend to think most (but not all) such materials were, if not entirely fabricated, then at least significantly modified in transmission. As Andrew Marsham wrote recently, “Some [documents] may be genuine, but the great majority of them were almost certainly invented purely to serve a narrative function.” In this regard, the architecture of Islamic histories fits well in the landscape of late antique Near Eastern historiographies. In some ways, however, this conclusion leaves more questions asked than answered. If it seems unlikely that the quoted materials in the histories “document” the events they describe, nevertheless historians of the period apparently found them to be indispensable tools for depicting the past. Why should this be? How did short passages of quotation relate to the broader narratives in which they were placed? In short, what did historians mean for such texts to do? In this paper, I examine the case of letters in Ibn A‘tham al-Kufi’s (fl. 3rd/9th) Futuh. First, I sketch out patterns in letters’ appearance throughout the entire work. Then, I consider the role that quoting letters plays in the narrative of a specific event (the ceding of the caliphate to Mu‘awiya b. Abi Sufyan by Hasan b. ‘Ali), revealing the particularity of Ibn A‘tham’s formulations by comparing his account to contemporary ones. Ultimately, I argue that, where modern historiography begins from the explication and interpretation of documents, Ibn A‘tham used the plastic form of the letters to work interpretations into his narrative structure. In particular, I show how the letters perform three functions: to catalyze narrative progress, to characterize the main actors, and to ethicize on their actions.