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