Musar su Salmi 112:1

And behold that there are many levels of repentance. It is true that you will find forgiveness for any repentance. However the soul will only find complete purification - to be as if the iniquities never had been - when a person purifies his heart and prepares his spirit, as will be explained. And so is it written (Psalms 32:2), "Happy is the man whom the Lord does not hold guilty, and in whose spirit there is no deceit." And it is like the matter of a garment that needs washing: For a little washing will be effective to remove its soiling. However, it will [only] whiten according to the amount of washing. And so is it written there (Psalms 51:4), "Wash me thoroughly of my iniquity." And the soul will be washed from iniquity according to how you wash its heart, as it is stated (Jeremiah 4:14), "Wash your heart clean of wickedness, O Jerusalem." And our Rabbis, may their memory be blessed, said (Avodah Zarah 19a), "'Happy is the man who fears the Lord' (Psalms 112:1) - when he is still a man." This means to say that the most elevated repentance of a man is in the days of his youth - [when] he overcomes his impulse when his strength is still with him. However any repentance is effective, as it is stated (Psalms 90:3), "You return man to dust; You said, 'Return you mortals!'" And our Rabbis, may their memory be blessed, said (Yerushalmi Chagigah 2:1), "Until the soul turns to dust."

The eighth [reason] is that in his getting on in days and the weakening of the strength of the impulse, he will not receive the [same] reward for the repentance as it would be for the refinement of his heart during the days of his youth. And our Rabbis, may their memory be blessed, said (Avodah Zarah 19a), "'Happy is the man who fears the Lord' (Psalms 112:1) - when he is still a man." And they [also] said (Sanhedrin 22a), "When the thief is lacking [what] to steal, he makes himself like a man of peace."

The general rule of this matter is that a man should never be stubborn and he should not "make his neck stiff" against those who rebuke him or against one who tries to teach him the upright way — but he should very willingly listen to them, and accept their words with the graciousness of his soul, for concerning stubborn people it is said : "Thorns and snares are in the way of the froward; He that keepeth his soul holdeth himself far from them" (Prov. 22:5). And it is also said "He that hath a froward heart findeth no good" (Prov. 17:20). In several instances are praised those who willingly listen to the words of the Torah, as it is written "But his delight is in the law of the Lord; And in His law doth he meditate day and night" (Ps. 1:2). And it is written "And he shall be like a tree planted by streams of water, that bringeth forth its fruit in its season" (Ps. 1:3); and it is written : "Happy is the man that feareth the Lord, that delights in his conmmandments" (Ps. 112:1). Notice that it says "delights" which means that a man must train himself to delight to do the commandments.