The being which has absolute existence, which has never been and will never be without existence, is not in need of an agent. - Moshe ben Maimon

Whatever God desires to do is necessarily done; there is nothing that could prevent the realisation of His will. The object of His will is only that which is possible, and of the things possible only such as His wisdom decrees upon. When God desires to produce the best work, no obstacle or hindrance intervenes between Him and that work. This is the opinion held by all religious people, also by the philosophers; it is also our opinion. For although we believe that God created the Universe from nothing, most of our wise and learned men believe that the Creation was not the exclusive result of His will; but His wisdom, which we are unable to comprehend, made the actual existence of the Universe necessary. The same unchangeable wisdom found it as necessary that non-existence should precede the existence of the Universe. Our Sages frequently express this idea in the explanation of the words, "He hath made everything beautiful in his time" (Eccl. iii. 11)... This is the belief of most of our Theologians; and in a similar manner have the Prophets expressed the idea that all parts of natural products are well arranged, in good order, connected with each other, and stand to each other in the relation of cause and effect; nothing of them is purposeless, trivial, or vain; they are all the result of great wisdom. ...This idea occurs frequently; there is no necessity to believe otherwise; philosophic speculation leads to the same result; viz., that in the whole of Nature there is nothing purposeless, trivial, or unnecessary, especially in the nature of the spheres, which are in the best condition and order, in accordance with their superior substance.

The proposition has... been laid down in the most general terms, "All evils are negations." Thus for man death is evil; death is his non-existence. Illness, poverty, and ignorance are evils for man; all these are privations of properties. ...The destruction of other things is likewise nothing but the absence of their form. After these propositions, it must be admitted as a fact that it cannot be said of God that He directly creates evil, or He has the direct intention to produce evil; this is impossible. His works are all perfectly good. He only produces existence, and all existence is good; whilst evils are of a negative character, and cannot be acted upon.

That which is impossible has a permanent and constant property, which is not the result if some agent, and cannot in any way change, and consequently we do not ascribe to God the power of doing what is impossible.