You must guard yourselves carefully, for you did not see any image on the day that G-d spoke to you at Horeb from the midst of the fire.
Deuteronomy 4:15
The word for “yourselves” (נפשותיכם) in the opening phrase of this verse literally means “your life.” We are therefore taught that this phrase also means that we must guard our safety and our health.
Thus, Maimonides writes that ensuring that the body remain healthy and strong is an integral part of the service of G-d, since “someone who is unhealthy cannot understand or have any knowledge of the Creator.” Jewish law thus requires us to follow the instructions of qualified health professionals.
The Maggid of Mezeritch stated further that “a small hole in the body produces a large hole in the soul,” meaning that our physical health affects our spiritual health. Thus, our physical health, safety and wellness is an inseparable part and parcel of our ongoing spiritual health.
— Daily Wisdom 3