If, G-d forbid, there is a plague in a city, he should fulfil the words of Chazal who said “Draw your feet in!” or flee the town and your life will be the spoils that you retain. A person should not speak like the fools who quote the verse “If Hashem will not guard a city there is no point in having a guard!” and they extrapolate from here that if Hashem wants a person to die then no effort to save oneself will help and if the will of Hashem is that he should stay alive, then even if he makes no effort at all to save himself he will still be saved for this is not the truth as we see that Hashem commanded us to be guarded and to guard our lives and even though Hashem can definitely keep a person alive even through a plague and conversely he can make a person die even without a plague, this does not constitute a contradiction to our obligation to make an effort to guard our lives as we have previously discussed that there are three types of decrees: 1) There are people whose merits are many and their Mazel is therefore very strong so that even if they do not go to a doctor and they do things which make their illness worse they nevertheless will not die but will live. 2) There are some people who have been sentenced to death (in heaven) and even if they would look after themselves with all of the ways of guarding themselves in the world, no doctor or effort can save them. 3) There are some people who because of their sins they are left to the laws of nature so that if he guards himself and follows the laws of nature with the cures which should work then he will live, whereas if he does not follow those laws, he will die. About such a person the verse says “And there are some who are gathered up without justice!”.
It follows that every person must worry that maybe he belongs to that group of people who are under the control of the laws of nature and he must therefore involve himself with cures when he is not well as if he does not do this and dies he will have sinned with his life as he has transgressed that which it says in the Torah “And you should be guarded very well for your souls!”. A person who does not guard himself or follow the rules of nature to seek the cure for his illness, besides for the fact that he will surely be punished for having transgressed an explicit commandment of the Torah, he also has the problem that it comes out that he is relying on a miracle and if a miracle is actually done for him, they will deduct from his merits.