On Prayer 5.3

And it is likely that the things that will be are not only foreknown by God but also preordained, and that nothing happens contrary to what he has preordained. Just as, then, if someone should pray for the sun to rise, he would be thought silly, asking that what will happen even without his prayer should happen through his prayer; so a man would be foolish who thinks that through his own prayer things happen which would in any case happen even if he did not pray. And again, just as a man would surpass all madness who, being troubled and scorched by the sun at the summer solstice, thought that through prayer the sun would be moved to the spring signs, so that he might enjoy temperate air; so if anyone thought that by praying he would not suffer the circumstances that necessarily befall the human race, he would surpass all melancholy madness.