In early quranic Manuscripts the name of the prophet ʾIbrāhīm occurs in two different spellings either ابرهم or ابرهيم . These two spellings are spread haphazardly throughout the Quran. Close examination of the patterns in the manuscript, however, show that the distribution of this spelling is not random or up to the whims of the scribe. The location where one spelling or the other occurs is highly correlated across the early manuscripts. Moreover, the location of one spelling or the other is highly correlated to where the quranic reader Hišām reads the name as ʾIbrāhām or ʾIbrāhīm. This paper argues that this is not because these manuscripts have been written in the reading of Hišām, but rather that Hišām based his reading on the rasm of the quranic text.