Our Sages said: “One who wishes to live, let him ‘kill’ himself” (Tamid 32a).There are two explanations of this saying: the first is that one should not live in an indulgent and luxurious manner, for if one does so then if at some time he finds himself in a situation of privation and hardship, and he will not be able to indulge as is his wont, is life will be unbearable and he is likely to fall into bad ways—to rob and steal and to do business unfaithfully—because his habits will have become necessities. Not so one who “kills” himself and trains himself to not insist on anything and to accept everything as all being equal. Such a person will live a good and long life with ease, and he will have no need to become a man of deceit.
It is thus also good for a person, even if Hashem graced him with wealth, honor and many possessions that he not let his children become accustomed to grandness and luxuries, for one never knows what the future has in store. The Torah testifies that once a child becomes accustomed to excessive food and drink, then even when he grows older he will not let go of his ways, and in the end he will rob from people. The Torah therefore instructed the teachings regarding the “wayward son,” for it is better that he should die when he is yet innocent rather than after becoming guilty with grave sins. We have seen with our own eyes how quite a number of people fell into bad ways as a result of their indulgent habits, and their end was bad, may Heaven spare us. And even if one does not end up falling into bad ways, one will still live a life of sorrow, and many times he will go hungry because he is unable to live on bread alone. But one who is accustomed to be satisfied with whatever is available, will be satisfied with even plain bread and that will be good for him.