The dominant interpretation of the origins of kharaj (land tax) and its transformation in early Islamic history betrays serious flaws. This interpretation has relied heavily on an uncritical reading of hadith collections and chronicle accounts that were compiled more than a century and a half after the conquest period, thus glossing over significant changes introduced over the course of the Arab conquest of kharaj lands in the Near East. My research proposes a fundamental revision to this interpretation by unraveling the controversial and complicated process through which kharaj was assimilated into Islamic law. The term kharaj appears in the Qur’an (23:72), however, it does not denote land tax. Whereas the Prophet Muhammad imposed jizya on the “People of the Book” and collected zakat from Muslims, his tradition included no levying of land tax. Historical and legal sources of early Islam credit the second caliph, ‘Umar (r. 634-644), with instituting land tax in Iraq—an institution that evidently derived from Sasanian and Byzantine tax practices. The sources, then, set out to construct narratives that effectively turned land tax into a category of Islamic law and a legitimate source of state revenue. To shed light on the process of narrative construction, I juxtapose early juristic texts such as Kitab al-Kharaj by Abu Yusuf, Kitab al-Kharaj by Yahya b. Adam, and al-Amwal by Abu Ubayd ibn Sallam, with the later conquest records supplied by al-Baladhuri, al-Tabari, and Ibn A‘tham al-Kufi, among others. Focusing on these juristic and historical sources, this research explores various ways in which the construction of the historical/legal narratives came about. I demonstrate that these sources shared a great deal of their content, their method of reporting (e.g., oral traditions that used chains of transmission for validation and were subsequently rendered into writing), and their use of Islamic salvation history that in the early Abbasid period created the notion of rashidun and incorporated policies introduced by the caliphs into the tradition corpus. Drawing attention to both commonalities and tensions that lay dormant in their narratives, I conclude that narrative construction allowed Muslim jurists to play an active role in public policy. The jurists ensured that the Islamic government depended on them for its laws to pass muster. This legal development additionally allowed the Islamic state to fend off charges of unethical tax extortion and legal malpractice.