This project will study the Arabic as it was spoken in the first centuries of Islam. Researchers have argued that this moment in history was a watershed moment for the Arabic language. The massive confluence of the Arab tribes and the dramatic increase of second-language speakers during the Arab conquests would have changed the Arabic language drastically from the complex Pre-Islamic Arabic into a simplified common form. These theories have been based on inferences from later periods. Written sources from this early period have not been used to further the knowledge of the spoken language at the time. The ever-present dominance of Classical Arabic as the written language has made it difficult to evaluate early Islamic linguistic material. Xeno-Arabic – Arabic as found in transcriptions and texts of Arabic in non-Arabic scripts – is a source of data that gives insight into the Arabic vernacular. There is a large corpus of not previously studied Xeno-Arabic material datable to the first centuries of Islam. This material can provide new insights into the spoken language of the period. This material is not bound by the linguistic norms and orthography of Arabic in the Arabic script, and therefore more closely reflects Arabic as it was spoken by the Arabic speakers of the early Islamic society. With new insights provided by Xeno-Arabic, we will be able to re-evaluate the language found in the early Islamic papyri written in Arabic script. For the first time it will be possible to use direct evidence of early Islamic Arabic to fill in a gap in our knowledge of the history of Arabic. Combining this with our vastly improved knowledge of Pre-Islamic Arabic, we can use these direct attestations to re-examine the changes that Arabic underwent during these formative centuries of Islamic society.