In Parshat Ekev (Dvarim 7:15) we are told:

This shall be the reward when you listen to these laws, and you observe and perform them; HaShem your God will safeguard for you the covenant and the kindness that he swore to your forefathers. He will love you and bless you and multiply you and he will bless the fruit of your womb and the fruit of your Land; your grain, your wine and your oil; the offspring of your cattle and the flocks of your sheep and goats; on the Land that He swore to your forefathers to give to you. You will be the most blessed of all of the peoples; there will be no infertile male or infertile female among you or among your animals. HaShem will remove from you every illness; and all the bad maladies of Egypt that you knew- He will not put them upon you, but will inflict them upon your enemies.

According to Sforno, “HaShem will remove from you every illness” indicates any manner of illness including those that are the result of climatic conditions. “Bad maladies” refers to those that are contagious. “That you knew” hints to the illnesses that the Egyptians were smitten with at the Sea of Reeds.

Sforno concludes that even though these diseases will strike your enemies, they will not infect you, as described in Tehilim 91:5-7:

You shall not fear the terror of night; nor the arrow that flies by day; nor the pestilence that walks in gloom; nor the destroyer who lays waste at noon. A thousand may fall victim at your side and a myriad at your right hand, but to you it shall not approach.

On the words “HaShem will remove from you every illness”, Ramban explains that God will take away ordinary ailments which occur in the world. “All the bad maladies of Egypt that you knew” are mentioned to insure the people that God “will inflict them upon your enemies.” Or maybe he is saying that by observing the laws they will be saved by the evil diseases, but if they do not observe them, the diseases will come upon them just as they came upon the Egyptians as it says in the chastisement (Dvarim 28:60) “He will bring back for you all the Egyptian diseases which you dreaded and the will cling to you.”

In Parshat BeShalach, Shmot 15:26 states: “He said to them: ‘If you vigilantly obey the voice of HaShem, your God, and do what is upright in His eyes, listen to his commandments and preserve all His statutes; then every sickness that I brought upon Egypt, I will not bring upon you, for I am HaShem who heals you.

Rashi brings the midrashic explanation that even if God does bring sickness, it is as if it were not brought because God will cure you. Rashi also brings the plain explanation: “for I am HaShem who heals you” means that God teaches you Torah and Mitzvot so that you will be saved from the diseases. It is like when a doctor tells a person: “Do not eat this particular thing lest it brings you to disease”, this represents following the mitzvot.     

Ramban does not agree with Rashi and explains the verse from Beshalach as follows: This is an admonition by which God warned them not to be among those who rebel against Him as the Egyptians had been. By listening to His voice, they will be saved from all sickness, since the sickness deservedly comes upon all those who rebel against His will, even as it befell the Egyptians when they did not listen to Him. This constitutes a promise that I will remove from you sickness that comes in the natural course of events, even as I healed the waters of Marah.

Where does this leave us today? Do we rely on God for our medical care? Is observing the mitzvot enough to heal us?

We must also do our part. When vaccines and medicines are available to us, we need to take advantage of them. When there are directives of how we need to take care of ourselves we must listen to them even if it is at the expense of praying indoors with a minyan. We lost too many people to Covid to continue our lives as usual and ignore medical advice.     

The following was presented by the Orthodox Union and the Rabbinical Council of America on December 15, 2020 based on the guidance of Harav Hershel Schachter and and Harav Mordechai Willig with the support of Harav Dovid Cohen:

We are grateful for the progress that has been made in vaccine development for COVID-19.  Halacha obligates us to care for our own health and to protect others from harm and illness. In addition, Halacha directs us to defer to the consensus of medical experts in determining and prescribing appropriate medical responses to both treating and preventing illness. There has long been an almost uniform consensus among leading medical experts that vaccines are an effective and responsible manner of protecting life and advancing health. For over two hundred years vaccinations have been responsible for the dramatic reduction of many terrible diseases and have significantly improved public health in our country and around the world. For this reason, the consensus of our major poskim (halachic decisors) is to encourage us to use vaccinations to protect ourselves and others from disease.

As I was entering a shopping mall today, I asked the guard if they are making sure that people are wearing masks. He said “Yes. It is very important. We must observe the mitzvah of ‘v’nishmartem me’od l’nafshoteichem’, ‘you shall greatly beware of your souls.’”