(4) There is no difference between a roof or anything else that is dangerous and likely to cause death to a person who might stumble. If, for instance, one has a well or a pit in his courtyard — — he must build an enclosing ring ten handbreadths high, or put a cover over it, so that a person should not fall into it and die. So too, any obstruction that is a danger to life must be removed as a matter of positive duty and extremely necessary caution.

(5) The sages have prohibited many things because they are dangerous to life. If anyone disregards them and says : "What claim have others on me if I risk my own life?" or: "I do not mind this," he should be lashed for disobedience.

(The midrash brings a quote from the tanach, and uses a story to explain it) "The merciful man does good to his own soul (Proverbs 11:17)," this [refers to] Hillel the Elder, who, at the time that he was departing from his students, would walk with them. They said to him, "Rabbi, where are you walking to?" He said to them, "To fulfill a commandment!" They said to him, "And what commandment is this?" He said to them, "To bathe in the bathhouse." They said to him: "But is this really a commandment?" He said to them: "Yes. Just like regarding the statues (lit. icons) of kings, that are set up in the theaters and the circuses, the one who is appointed over them bathes them and scrubs them, and they give him sustenance, and furthermore, he attains status with the leaders of the kingdom; I, who was created in the [Divine] Image and Form, as it is written, "For in the Image of G-d He made Man (Genesis 9:6)," even more so!...

(3) He who follows the medical directions, but sets his heart merely to keep his body and limbs healthy and beget children to do his work and strive for his needs, such is not the good way. But he should set his heart to have a sound and strong body so that his soul be tranquil to acquire the knowledge of the Lord; for, it is impossible that one should comprehend and improve himself in scholarship when he is hungry, or sick, or when one of his limbs pains; but he should set his heart to have a son who, perhaps will be a great sage in Israel Consequently, one who follows such way all of his life, is constantly in God's service, even when he is buying and selling, even when he performs the grossest duty, seeing that his thought beneath it all is to find enough to satisfy his wants, so that his body be sound, ready to serve God. Even when one sleeps, if his sleep be purposeful so that his mind be rested, and rests his body so as to prevent himself from becoming sick and be unable to serve God as a result of sickness, it will be found that even his very sleep is part of his service to God, blessed is He! And on this subject the sages commanded and said: "And let all thine actions be with devotion to the Name of God" (Pir. Av. 2.12); and, concerning this Solomon in his wisdom said: "In all thy ways acknowledge Him, and He will make level thy paths" (Prov. 3.6).

(1) Seeing that the maintenance of the body in a healthy and sound condition is a God-chosen way, for, lo, it is impossible that one should understand or know aught of the divine knowledge concerning the Creator when he is sick, it is necessary for man to distance himself from things which destroy the body, and accustom himself in things which are healthful and life-imparting. These are: never shall man partake food save when hungry, nor drink save when thirsty; he shall not defer elimination even one minute, but the moment he feels the need to evacuate urine or feces he must rise immediately.

I say that this is also from the sparks of a person's soul; that is to say that a person descends to this world with 288 sparks to raise up, and all the nourishment of a person, or clothing of a person, or a person's dwelling place, or vocation all is to raise the sparks of their own self. And sometimes a person loses in their endeavors in their vocation, and has not yet corrected what they need to correct. And sometimes a person succeeds, and in the success that brings them joy and pleasure in that they raise up the sparks, as has been explained in the writings of the ARY, may his memory be a blessing, see further there. 

It has already been explained above (Letter 150) that Proverbs 3:6 "Know Him in all your ways" - that all your ways should be for the sake of heaven...This is a a great principle in all your actions. That you should do them for the sake of heaven, and immediately as you do the action, find a way to make it in service of the Blessed One, for example when you eat, don't simply say that the purpose of my eating is so that I will have strength afterwards to serve the Divine (even though this is a worthy intention) but the more wholesome way is that there should be something immediately [in the process of eating itself] for the sake of Heaven. And this means to raise the sparks. And on Shabbat each meal has its own intention, as is known...and this is the same for all the actions of a person. And in the manner a wise person will understand and take this to heart. 

I heard from my teacher an explanation of the Talmudic story (Taanit 22b) of the two jesters that were in the market, who were making people laugh, and Elijah the prophet explained that they were righteous and worthy of reward in the world to come. He asked for an explanation of this story in a private meditation and prayer. And he was told that the explanation of the two jesters was that their entire venture was to connect with each person in their audience, and to unite the essence of that person to the Holy Blessed One and the Shechinah. And they did this through the details of each person's daily activities, or their business, in the large and small things. Except that someone who was suffering, or depressed - God forbid! The jesters were not able to reach that person's essence or connect with them, and they had to tell jokes until the person was joyous, and the jesters could connect with that person, and then join that person to the Blessed Name. This is a great principle, understand it! The words of the wise are grace.