This article ethnographically analyzes the everyday negotiations of a language policy at a private religious educational institution whose explicit educative mission is the transmission of religious beliefs, values, and practices. Specifically, it explores a Hebrew-only language policy at a Jewish day school located in New York City, and focuses on two interrelated questions: (1) how do students and teachers enact and challenge the Hebrew-only policy in daily classroom practices; and (2) how does this policy become a cultural practice in the classroom, and to what effect? My analysis highlights the paradoxical nature of religious language policy in education. Specifically, it shows that the students and teachers widely embrace the Hebrew-only policy, agreeing that Hebrew language education is critical to the educative mission of instilling Jewish identity. However, in practice, the policy presents challenges to teachers and students due to varied Hebrew proficiency among students and their teachers, and the complex reality of teaching and learning a language that is not widely known or used in the community. This tension between ideology and enactment produces a unique set of cultural practices in the school that results in questionable language learning achievements, but that paradoxically reinforces the underlying goals of the policy: a reaffirmation and strengthening of the students' sense of religious identification. The article concludes with a discussion about the complexity of defining and implementing religious language educational policy.