In the research described in this paper, we explored the way Palestinian teachers use the Arabic language to teach mathematics in Arabic. First, we address the issue from an historical overview of the context of study. The historical overview allows us to situate the current context of teaching mathematics in Arabic in Palestine. We rely on Halliday's concept of register to define what we call "Mathematical Arabic For Teaching". It allows us to focus our study, and to address the issue of combination between this register to be developed by the teachers and the Arabic textbook content. Our theoretical framework is based on a combination of the theories Documentational Approach to Didactics and Mathematical Discourse in Instruction, which allows us to discuss mathematical Arabic for teaching as a resource. We based our exploratory study on the case of three teachers, chosen according to well-defined criteria. We explored the issue through audio recordings of their lessons teaching tenth graders the signs of quadratic functions, and video recorded interviews on their reflections on those lessons. We identified three combinations between the teachers' Mathematical Arabic For Teaching and the use of the mathematics textbook, namely, complementarity, tension and equivalence. We conclude with some implications of these forms of combination.