It can be said that God in the first creation of things decided to produce effects regularly in the presence of, and not in the absence of, certain things and each thing of the same species. And it belongs to these things to be a cause by their nature, i.e., by that nature in which they were constituted at their creation. And the term 'regularly' is used because God did not tie His power down to the creatures.

gabriel biel, whether the sacraments of the new covenant are effective causes of grace p. 4

This argument seems strong to me and sufficiently plausible for us to conclude that if God were to decide that from this day forward He is going to will to send rain at the utterance of some word pronounced by someone, then that word, once uttered, would be just as properly a cause of the rain brought about by God at its utterance as heat is a cause of heat. And this seems altogether true. For a creature has nothing except from God's will alone, which grants it to the creature freely and contingently.

gabriel biel, whether the sacraments of the new covenant are effective causes of grace, p.3-4