Here, Maimonides sets out the philosophers’ proof for the existence of God. At the end of this, he declares:

If the spheres are transient, then God is their Creator: for if anything comes into existence after a period of non-existence, it is self-evident that an agent exists which has effected this result. It would be absurd to contend that the thing itself effected it. If, on the other hand, the heavenly spheres be eternal, with a regular perpetual motion, the cause of this perpetual motion, according to the Propositions enumerated in the Introduction, must be something that is neither a body, nor a force residing in a body, and that is god, praised be His name! (هو الالاه جل أسمه)