Musar su Salmi 118:18

And a person is obligated to reflect and know that the troubles that find him and the afflictions that come upon him are not according to the greatness of his iniquity and the multitude of his sins. Rather God, may He be blessed - in His pity upon him - afflicts him in the way of the rebuke of a father upon his son, as it is stated (Deuteronomy 8:5), “And you shall know in your heart, that, as a man chastens his son, so the Lord, your God, chastens you.” And our Rabbis, may their memory be blessed, explained (Yalkut Shimoni on Torah 350), “Your heart knows the deeds you have done and the afflictions I have brought upon you; that it is not according to your deeds that I have afflicted you.” And it is stated (Job 11:6), “and know that God has overlooked for you some of your iniquity.” And it is stated (Ezra 9:13), “though You, our God, have been forbearing, [punishing us] less than our iniquity.”
But when reproof comes upon the enemies of the Lord, may He be blessed, they are finished with one iniquity - for the punishment comes all at once, as it is stated (Psalms 34:22), “One misfortune is the deathblow of the wicked.“ So the rest of their iniquities remain upon their souls, as it is stated (Ezekiel 32:27), “and their iniquities shall be upon their bones.” However when reproof comes to the righteous, it comes little by little, until the termination of their iniquities, as it is stated (Amos 3:2), “You alone have I known from all the families of the earth; that is why I will call you to account for all your iniquities.” And our Rabbis, may their memory be blessed, explained (Avodah Zarah 4a), “It is comparable to a person who lends money to two people, one of whom is his friend, and the other one is his enemy. [In the case of] his friend, he collects from him little by little; [whereas in the case of] his enemy, he collects from him all at once.” And it is stated (Proverbs 24:16), “Seven times the righteous man falls and gets up, while the wicked are tripped by one misfortune.” Its explanation is that they stumble upon one misfortune and are finished. And it is stated (Jeremiah 10:24), “Chastise me, O Lord, but only in judgement; not in Your wrath, lest You reduce me to naught.” Its explanation is, “but only in judgement”- with the trait of mercy and and the property of Your kindness. [This is] from the usage (in Numbers 29:18), “in their count according to [their] judgement,” [which means] according to [their] property; [and in] (Psalms 112:5), “who conducts his affairs in justice,” [means] with measure. And they compared it to another parable regarding this matter and said (Midrash Tehillim 18), “One who does not know [how] to hit will hit his son in his eyes and in his face; whereas one who knows [how] to hit will hit his son in such a way that it will not cause him damage.” And likewise is it written (Psalms 118:18), “The Lord surely chastised me, but He did not give me over to death.” And it is stated (Job 2:6), “but only spare his life.”
And He only brings vengeful afflictions upon the evildoers. But probing afflictions only come upon the righteous; for they accept them with love and they increase the refinement of their actions. So [these] afflictions are for their good and their benefit, and the increase of their reward - as it is stated (Psalms 11:5), “The Lord probes the righteous one.” And our Rabbis, may their memory be blessed, compared it to a parable regarding this and said (Bereishit Rabbah 58:32), “When the owner of the flax knows that the flax is strong, he hits it much in order to make it soft and good.”

“As soon as my son’s soul went out, it encountered my soul ascending from the immersion mentioned earlier. It was then that the decision was made to grant me another twenty-two years of life on account of my son’s tears and words. Now that I have been purified and my soul is pure and unsullied, it is essential that during these twenty-two years I engage only in matters pertaining to the World to Come. For I have already experienced the judgment of death and immersion in Gehin- nom. Now I must see to it that I will not be ashamed in the World to Come. “This is what Dovid HaMelech meant when he said, ‘God has severely afflicted me, but He did not deliver me unto death’ (Tehillim 118:18). That is, Dovid said, ‘I see that the Holy One Blessed is He has subjected me to many painful afflictions. But this was only to cleanse me of sin. And now that I have been purified through the “immersion” of afflictions, I must be certain not to sully my soul again from this time forth, Heaven forbid. Rather, Open for me the Gates of Righteousness (ibid. 19), so that I may toil only in Torah and awe of Heaven in order that I will not be ashamed in the World to Come.’”

The letters of the Ineffable Name spelled in words יוד-הי-ויו-הי, total 72 in numerical value, as does a different kind of spelling called גלגול י-ה-ו-ה י-ה-ו י-ה י. This combination too totals 72. In that combination the first name symbolizes the original Existence, the mystery of G–d's Essence, the second three-lettered name which totals 21 symbolises that G–d created the universe out of "nothing," and the fact that He existed independent of such a universe. The name א-ה-י-ה which also totals 21, being a form of the future tense, tells us that in the future G–d will reveal Himself. The name י-ה, is also used in the past tense in Job 17,6 "ותפת לפנים אהיה," "I have become like Tophet of old." This means that the name א-ה-י-ה i.e. the "three-lettered name י-ה-ו," is a development of the original four-lettered name. The name י-ה is employed to remind us of how G–d guides history and the fate of man through the system of reward and punishment. A typical example is Psalm 130,3: אם עונות תשמר י-ה מי יעמוד? "If You keep account of sins, O Lord, Lord who will survive?" Another well known example of the use of that two-lettered name of G–d is Psalms 118,18: יסר יסרני י-ה ולמות לא נתנני, "The Lord punished me severely, but did not hand me over to death." On the other hand, the same name is used when discussing man's reward, such as in acknowledging Israel's salvation from the pursuit of the Egyptians in Exodus 15,2: עזי וזמרת י-ה ויהי לי לישועה, "The Lord is my strength and might; He is become my deliverance." Another example is Psalms 118,5: מן המצר קראתי י-ה ענני במרחב י-ה, "In distress I called on the Lord; the Lord answered me and brought me relief."