“My child, do not despise Hashem’s discipline, and do not spurn His reproof” (Mishlei 3:11)
“Hold fast to discipline; do not let go. Guard it, for it is your life” (ibid. 4:13)
“You will groan at your [life’s] end when your flesh and your body perish Then you will say: How could I have hated discipline, and my heart loathed rebuke?” (ibid. 5:11-12)
The Lev Eliyahu (III, pg. 364) asks the following incisive question: Why isn’t it sufficient to say, “You will groan at your end… you will say, ‘How could I have hated discipline…’”? Why the necessity to add, “When your wealth will be in a stranger’s house”?
Let us imagine a destitute man, who does not have clothing to cover his body. He borrows money on interest and purchases a suit. He does not have the money to pay back either the capital or the interest. Obviously, his debt increases daily. After a few years, the suit becomes worn-out and once again, he is left without clothes. The weather is freezing and he is now bereft of his clothes, as well as having his original debt.
You will groan at your end, when all earthly pleasures are gone. But the debts accrued on their behalf are not. Then you will bewail your plight, crying out, “How could I have hated discipline, and my heart spurned reproof?” It is better to pay up your debts now.
“For a commandment is a lamp and the Torah is light; and the reproof of mussar is the way of life” (Mishlei 6:23)
Rashi explains that the “reproof of mussar” steers one in the way of life. It is therefore called the way of life.
The Malbim says that mussar compels a person to do something, whereas rebuke convinces the mind to act. But the mussar in this sefer (Mishlei) refers to Fear of Heaven, as the pasuk states (ibid., 15:33), “Fear of Hashem is the discipline (mussar) of wisdom.” Through Fear of Heaven, one arrives at proper understanding. He will then be able to access his own intellect and go on the road of life.
The Maharal says that words of reproof (mussar) offer a person length of days and protection from death. By means of a mitzvah, compared to a lamp, and Torah, compared to light, one attains the hidden light reserved for the tzaddikim. A mitzvah has the potency of a lamp, whereas the Torah is eternally effective, through studying it together with mussar. Its powers of reproof protect a person from death (Derech Chaim, Introduction).
The words of mussar mentioned in the Talmud and other places refer to correct interpersonal relationships. One who does not follow certain mussar exhortations, is sinning severely. One must therefore be exceedingly careful concerning them. Mussar is called by this name (מוסר) because it afflicts (מייסר) a person who considers going astray (Maharal, Netiv Derech Eretz 1).
“The ear that hears life-giving rebuke will abide in the midst of the wise” (Mishlei 15:31)
>The Metzudat David expounds: The ear that listens to rebuke, which provides life, will eventually be inclined toward wisdom and will reside among the Sages, to hear their words of wisdom.
The sefer Shiurei Da’at (III, pg. 103) states that one should study mussar and use all his energy to elevate himself and become enthusiastic over spiritual matters. If one studies the words of the holy Sages carefully, and takes the words of a subject or saying which draws his heart and awakens his soul and spirit and puts them to a fitting tune, he will certainly be drawn toward the fulfillment of that saying. Then he will become completely elevated, through all he has learned and by using all of his powers.
