In the ancient Near East, the transmission of texts was inextricable from processes of revision. Scribes, at least those in positions of authority, made adjustments to their received material. Whether these alterations took the shape of exegetical glosses, omissions, or major additions, they were intended to have some sort of impact on the older work. As a general rule, however, even the most substantial changes were tied to a basic tendency to preserve, rather than discard, the received text. This is evident both in literature from Mesopotamia, where we have access to copies of the same work from different periods, and in the Bible, where inconsistencies preserved in the final form of texts indicate the work of multiple hands. If we wish to use these works to tell us something about ancient history, religion, culture, and political structures, especially with attention to settings in real time, we first must attempt to reconstruct the processes by which they evolved. While such efforts are conducted widely on a case-by-case basis, there remains a need to develop a better sense of the actual methods that scribes used to revise their texts. With this dissertation, I aim to help remedy this by presenting a study of one of the most prominent tools in the scribal repertoire, what I refer to as "revision through introduction." With this tool, scribes could alter the reception of older works by adding new material to the front. This method had potential for enormous impact. Because the secondary contribution was at the beginning, the content of the older work was automatically reinterpreted through the new lens. Though some additions were merely used to complement the older work, others were extensive contributions that were designed to transform the reception of the prior text completely. In a number of cases, both biblical and Mesopotamian, this has led to misinterpretations of the texts at earlier stages of development. By tracking the use of revision through introduction across a wide range of examples in the Bible and in Mesopotamian literature, I aim to provide a model both for identifying other cases of revision through introduction and for interpreting these works more accurately in light of their complex transmission histories. Rather than treat the Mesopotamian evidence as an empirical model for examining revision in the Bible, I use findings from both corpora to develop a more nuanced understanding of this ubiquitous and most effective tool for reworking ancient texts.