Maimonides' View of Circumcision as a Factor Uniting the Jewish and Muslim Communities

L. Kaplan, in his paper "Maimonides on the Singularity of the Jewish People," ¹ proposes the following thesis:

. . . for Maimonides, even Muslims, for example, would be members of the Abrahamic community, since "they confess the unity of God, with a proper unity," ² that is, that they are genuine theists.