Musar su Salmi 37:1

He whose nature is overcome by this disposition is blameworthy, for it leads him to envy, and a noble man is never found to be envious. Books (i.e., of poetry) have been filled with the censure of envy, and every man of intelligence knows how much has been said as to its baseness. It is necessary to turn from it, for frequently the affairs of the envious lead him to use violence. Thus it is said of such as these (Micah ii. 2), "And they covet fields and take them by violence." Enviousness is a loathsome trait. The wise man must keep himself as far from it as he can, for he gains no advantage through it: on the contrary, continued depression and fatigue of the spirit through desires and the constant hatred of men, scantiness of repose, preoccupation of the mind, apprehensiveness and the punishment of God, for transgressing that which He forbade in His revealed Scripture. Man must not be jealous of unrighteous men, because he sees them devote themselves to pleasure and (the gratifying of) passions. But let him employ his zeal in the service of God. Thus the sage said (Prov. xxiii. 17), "Let not thy heart be envious of the sinners." Again he spake (Ps. xxxvii. i), "Be thou not envious against the workers of iniquity."

When Rabbi Yehudah and Rabbi Yitzchak arrived he approached them and related to them what had happened. Rabbi Yehudah told him, “You did the right thing. Come with us and we will sit and listen to what you have to say.” The child said, “I am tired, for I have not eaten anything today.” They took out some food and gave it to him. A miracle occurred for them and they found a spring under a tree and drank from it. Then the child began, “It is written, ‘For Dovid, do not grieve over the [success of] evildoers; do not be jealous of the iniquitous’ (Tehillim 37:1). That is, do not turn to observe the deeds of the wicked, for perhaps you will not be jealous on behalf of Hashem of Hosts and you will be punished on this account. For whoever sees the deeds of the wicked and is not jealous for the honor of the Holy One Blessed is He transgresses three injunctions: 1. ‘Do not have any other gods before me’ (Shemos 20:3). 2. ‘Do not make for yourself an image nor shall you bow to them’ (ibid. 4-5). 3. ‘Do not serve them’ (ibid. 5). “Therefore a person must separate from them and direct his path away from them. For this reason I separated from the old man and directed my path away from him. And now that I have found you I will explain another verse.” So he began, “And He called (ויקרא) to Moshe” (Vayikra 1:1) — “The alef (at the of the word vayikra) is written small because this ‘calling’ was not complete. Why not? Because it took place outside the land of Israel. For completion exists only within the land.”

In the measure in which man separates himself from baseness does he near God, may He be exalted; and in the measure in which he nears baseness, does he separate himself from Him. Now in regard to the twenty qualities of man, David, peace be upon him, points to them and alludes to their origin in the "Psalm of David" (Ps. xxxvii. 1) "Contend not with thyself because of evil-doers." Of some of these he clearly treats, as may be gathered from the literal interpretation of the verse; others he indicates merely by allusions: viz., he enjoins serving God, by cultivating qualities that are praise-worthy, and inhibits the exercise of the blameworthy qualities. Furthermore, he condemns the course of those who depart from the right way, as it should be observed, and praises the course of those who rightly habituate themselves to good practice.