Maimonides famously holds that, while it is perfectly possible to know (and say) that God exists, it is impossible to know (and say) what God is like because any positive attri- bution contradicts God’s essential oneness. Consequently, pure equivocity obtains between descriptions of the divine and descriptions of any other being. But this raises a puzzle: Knowledge of God seems vacuous if we lack all comprehension of God’s nature - so how can we have any comprehension of the divine without being able to say what it is that we know? In this essay, I defend the substantiality of the concept of knowledge of God on Maimonides’ apophatic picture. Drawing on the concept of non-propositional knowledge, I argue that knowledge and comprehension can come apart, which lends support to Maimonides’ thesis that knowledge of God, though substantial and objective, cannot be expressed.