Tefillah as Hishtadlus within Nature

Teβillah is Hishtadlus

One of the wonders of tefillah is that it can be considered as hishtadlus b'derech hatevah (hishtadlus within natural means) because Hashem put into the rules of nature that tefillah helps.

Rashi (32:9) writes, דברים לשלשה עצמו התקין ולמלחמה לתפלה לדורון, "Yaakov prepared himself [for meeting Eisav] in three ways: with a gift, with tefillah, and with war tactics." Gifts and warfare are hishtadlus within the rules...