The Mishnah in Pirkei Avot states: “Be cautious regarding Keri’at Shema and prayer.”
The Gemara (Mo’ed Katan 28a) states: “Children, life, and sustenance are not contingent on one’s merits; rather, they are contingent on one’s fortune.” This means that the matters of one’s children, longevity, and livelihood depend on one’s personal fortune and will do not change based on one’s merits.
Nevertheless, Maran Rabbeinu Ovadia Yosef zt”l writes that through prayer, one can change all three things for the better. Even if, based on one’s fortune, one is destined to be destitute, childless, and die at a young age, through prayer, one can change one’s luck to be wealthy, have many children, and live a long and productive life.
Maran zt”l proves this from the words of the Tosafot (Sotah 10b) who write that King David’s prayer saved his son, Avshalom, from enduring the tortures of Gehinnom although his actions certainly warranted this.
Maran zt”l adds that this is hinted in the verse (Shemot 23) which states, “And you shall serve Hashem, your G-d and He shall bless your bread and your water; I shall remove illness from your midst. There shall be not miscarrying or barren woman in your land and I shall fill the number of your days.” “And you shall serve Hashem your G-d” refers to prayer, as the Gemara (Ta’anit 2a) states, “What is service of the heart? This refers to prayer.” Following this, the verse states, “He shall bless your bread and water,” which refers to one’s sustenance. “There shall be no miscarrying or barren woman in your land” refers to one’s children. “I shall fill the number of your days” refers to one’s longevity. We see clearly that prayer can positively impact these three aspects of life, as long as one prays with due concentration.
Prayer held after Torah study is considered especially beneficial, as the holy Zohar (Parashat Pinchas) states: “Come and see, before the Torah was given to the Jewish nation, all creatures upon the face of the earth were contingent of fortune. After the Torah was given to the Jewish nation, however, Hashem extracted them from the destiny of the stars and constellations. We see this regarding Avraham Avinu, for according to his destiny, he was not to bear any children. However, Hashem told him to ignore the stars and he bore a son.”
We see from the above the great power of prayer and Torah study. Not only do these forces impact the outcomes of physical and material matters, rather, Torah study and prayer can even overcome other sorts spiritual powers, more than any other force or “Segula” (protective amulet) in the world. (See Maran’s Anaf Etz Avot, page 146.)
