Between 1614 and 1617, Hugo Grotius wrote a treatise entitled De imperio summarum potestatum circa sacra. Though the work was published much later (posthumously in 1647), it should be read in the context of Grotius’s involvement in the controversy associated with the Oath of Allegiance to James i and the conflict between Remonstrants and critics of the government in the 1610s. In De imperio, Grotius uses classical and contemporary sources to argue for government oversight of the churches. This article focuses on one biblical passage that figured prominently in the debate over state control of religion, Numbers 27:18–21. Grotius’s remarkable treatment of this passage shows how a leading figure in the Republic of Letters used the tools of historical and literary criticism to gain leverage in an ongoing hermeneutical debate, thus shedding light on the relation of irenicism to critical exegesis of the Bible.