It is related that once a woman from a family that was not observant came to the Hazon Ish (Rabbi Avraham Karelitz, outstanding Talmudic scholar and leader of religious Jewry in Israel). Crying bitterly, she told the rabbi that her twelve-year-old son had contracted a dangerous blood disease and was at death`s door. The physicians in Beilinson Hospital in Petah Tikvah in Israel could offer no hope.
"What is the boy`s name?" the Hazon Ish asked. "Hayyim," the distraught mother replied.
The Hazon Ish assured her, "If you promise that the child will put on Tefillin every day when he reaches the age of thirteen, God will have mercy on him."
The woman promised by everything dear and holy to her. She lost no time and ran to her son`s bed, and the doctors told her that his condition had improved. The child recovered within a few days, and when he turned thirteen, not only did he put on Tefillin, the father also returned to Judaism in the wake of his son`s recovery.