Truly this should be made known as a cardinal principle, that as with a victory over a. physical obstacle, such as in the case of two individuals who are wrestling with each other, each striving to throw the other— if one is lazy and sluggish he will easily be defeated and thrown, even though he be stronger than the other, exactly so is it in the conquest of one's evil nature; it is impossible to conquer it with laziness and heaviness, which originate in sadness and in a heart that is dulled like a stone, but rather with alacrity which derives from joy and from a heart that is free and cleansed from any trace of worry and sadness in the world.

As for what is written, "In all sadness there would be profit," which means that some profit and advantage would be derived from it, the phrase, on the contrary, indicates that sadness in itself has no virtue, except that some profit is derived and experienced from it, namely, the true joy in the Lord G‑d which follows from genuine anguish over one's sins, at propitious moments with bitterness of soul and a broken heart. For thereby the spirit of impurity and of the sitra achra is broken, as also the iron wall that separates him from his Father in Heaven, as is commented in the Zohar on the verse, "A broken and a contrite heart, O G‑d, Thou wilt not despise;" then will be fulfilled in him the preceding verses: "Make me hear joy and gladness... Restore unto me the joy of Thy salvation, and uphold me with Thy generous spirit."

This is the simple reason why Rabbi Isaac Luria, of blessed memory, instituted the recital of this Psalm after the Midnight Prayer, before commencing study, in order to study with the true joy in G‑d which succeeds remorse. For such joy has an excellence similar to that of a light emerging from the very darkness, as is written in the Zohar on the verse, "Then I saw that wisdom excelleth folly as light excelleth darkness." Note there, and it will suffice for him who understands. Furthermore, Scripture states it explicitly: "Because thou didst not serve the Lord thy G‑d with joyfulness,..."— and everyone is familiar with the commentary of Rabbi Isaac Luria, of blessed memory, on this verse.

The following is sound counsel as to how to cleanse one's heart of all sadness and of every trace of worry about mundane matters, even about "Children, Health and Sustenance." Everyone is familiar with the statement of the Rabbis that "Just as one must recite a blessing for the good, [one must also recite a blessing for misfortune]." In the Gemara it is explained that one should accept [misfortune] with joy, like the joy of a visible and obvious benefit, For "this is also for the good," except that it is not apparent and visible to mortal eyes, because it stems from the "hidden world" which is higher than the "revealed world," the latter emanating from the letters vav and hai of the Tetra-grammaton, whereas the "hidden world" represents the letters yod— hai. Hence the meaning of the verse, "Happy is the man whom Thou, O G‑d, chasteneth." Therefore, the Rabbis, of blessed memory, commented that it is to those who rejoice in their afflictions that the verse refers: "But they that love Him shall be as the sun going forth in its might." For this is the joy of desiring the nearness of G‑d more than anything in the life of this world, as is written, "Because Thy loving-kindness is better than life,.. ," and the nearness of G‑d is infinitely stronger and more sublime in the "hidden world," for "The concealment of His strength is there," and "The Most High abides in secrecy." Therefore, [the man who accepts affliction with joy], merits [to see] the "Sun going forth in its might"— in the world to come, i.e. the sun emerging from its sheath in which it is enclosed in this world. But in the world to come it will appear out of its covering, meaning that then the "hidden world" will be revealed and will shine and send forth light in a great and intense revelation to those who had taken refuge in Him in this world and had taken shelter under His "shadow"— the shadow of wisdom (chochmah), i.e. in the sense of "shade" as differing from light and revealed goodness. Suffice it for him who understands.

As for the sadness which is connected with heavenly matters, one must seek ways and means of freeing oneself from it, to say nothing of the time of Divine Service, when one must serve G‑d with gladness and a joyful heart. But even if he is a man of commerce and worldly affairs, should there enter into him any melancholy or anxiety about heavenly matters during the time of his business affairs, it is clearly a machination of evil impulse in order to lure him afterwards into lusts, G‑d forbid, as is known. For were it not so, whence would a genuine sadness, which is one that is derived from love or fear of G‑d, come to him in the midst of his business affairs?

Thus, whether the melancholy encroaches on him during Divine Service, in study or prayer, or not during Divine Service, he should tell himself that now is not the time for genuine anxiety, not even for worry over serious transgressions, G‑d forbid. For, for this, one needs appointed times and a propitious occasion, with calmness of mind to reflect on the greatness of G‑d, against Whom one has sinned, so that thereby one's heart may truly be rent with sincere contrition. It is explained elsewhere when this time should be, and it is there explained also that as soon as his heart has been broken during these specific occasions, he should forthwith completely remove the sorrow from his heart and believe with a perfect faith that G‑d has removed his sin in His abundant forgiveness. This is the true joy in G‑d which comes after the remorse, as mentioned above.