…the Mishnah shapes a complex attitude towards evil. When bad things are still avoidable, a person ought to fight them with all his strength. He should act on his own and petition God up to the last moment. But once the events have actually occurred, he has to shift from demand to acceptance.
If we understand the concept of vain prayer within the larger context of the obligation to thank God for the bad, it follows that the vainness of prayer for past events is not dependent on the argument that backward causality is impossible, logically or otherwise. The point of the Mishnah is not that by asking God to undo the past we request what is impossible or absurd. The crucial third mishnah that limits prayer deals with a different problem altogether. The basis for such a limitation on prayer is not the limits of logic but the limits of complaint. There is no need to take a stance on the deep metaphysical problem concerning the logical possibility of backward causality, since the point of the Mishnah concerns not metaphysics but the nature of the religious and human stance towards the world.
Mosha Halbertal, “The Limits of Prayer”, Jewish Review of Books (Summer 2010), 43, 44.