Commento su Ecclesiaste 11:9

Rejoice young man in your youth. As a person who says to his servant or to his child, “Persist in your sinning, but [realize] you will be punished in one blow for all [your sins].” Here too, the wise man says, “Rejoice, young man in your youth ... follow the ways of your heart,” but be assured “that for all these things,” the Judge “will bring you to judgment.”²⁵Alternatively, the Gemara in Maseches Shabbos 21b states that what is learned in the years of childhood is remembered more readily. This is the time period that one has no distractions or troubling thoughts. (Sforno)

“Rejoice, young man, in your youth. Let your heart cheer you in the days of your youth. Walk in the ways of your heart and in the sight of your eyes, but know that for all these, God will bring you to judgment” (Ecclesiastes 11:9).
“Rejoice, young man, in your youth” – Rabbi Shmuel bar Rabbi Yitzḥak said: The Sages sought to suppress the book of Ecclesiastes because they found in it matters that tend toward heresy. They said: Is this the wisdom of Solomon, that he said: “Rejoice, young man, in your youth”? Moses said: “Do not stray after your heart” (Numbers 15:39), and Solomon said: “Walk in the ways of your heart.” Has restraint been loosened? Is there no judgment and no Judge? When he said: “For all these, God will bring you to judgment,” they said: Solomon has spoken well.
Rabbi Ḥiyya the Great and Rabbi Shimon ben Ḥalafta: Rabbi Ḥiyya the Great said: [This is analogous] to one who fled from the inquisitor.³⁶An officer who would interrogate suspects, often by means of torture. He was running, and [the inquisitor] was pursuing him. They said to him: Minimize your running so you will not have to travel far to return.³⁷When they catch you, you will not have to suffer as much from their treatment as they force you to walk back. So too, “but know that for all these, God will bring you to judgment.” Rabbi Shimon ben Ḥalafta said: [This is analogous] to one who was sailing on the river. He was fleeing and they were pursuing him. They said to him: Minimize [how far] you enter [the river] so you will not have so far to exit that you will tire. So too, “but know that for all these, God will bring you to judgment.”
Rabbi Ḥanina bar Pappa said: [This is analogous] to one who would steal the tax.³⁸He would transport goods across the border without paying taxes. One time they apprehended him. They said to him: ‘Give us what you have with you.’ He said to them: ‘Take what I have with me.’ They said: ‘You think that we are going to take only what you have with you now? We are demanding from you everything that you have with you, and everything that you have stolen all these years that you have been stealing.’ So too, “but know that for all these, God will bring you to judgment.”
Rabbi Levi said: [This is analogous] to a bird that was trapped in a cage. A certain bird came and stood near it. It said to [the bird in the cage]: ‘Happy are you that your food is provided for you.’ [The caged bird] said to it: ‘Unlucky and unfortunate one. You are looking at my food, but my captivity you do not see. Tomorrow they will take me out and slaughter me.’ So too, “but know that for all these, God will bring you to judgment.”
Rabbi Tanḥum said: [This is analogous] to a wicked person who came to a storekeeper. He said to him: ‘Give me fat meat, aged wine, and various delicacies.’ He ate, drank, became intoxicated, and sought to leave. [The storekeeper] said to him: ‘Give me the payment for what you ate.’ He said: ‘The stomach of this man is before you. Cut it open.’³⁹You can take back what I ate. The storekeeper was clever. What did he do? He took a mat and wrapped him in it and placed him at the entrance to his store. To anyone who passed, he said: ‘Toss⁴⁰Toss money into the bowl. and perform charity for this dead person, so we will purchase a shroud for him.’ A certain contemptible, ill-mannered person passed. He said to [the storekeeper]: ‘This unlucky, unfortunate person is still cast here?’⁴¹This passerby was a friend of the other wicked person and understood why he was wrapped in the mat there. He was telling the storekeeper to let him go. He said to him: ‘By your life, wait until I recover my money.’ When he had recovered his money, he said to him: ‘Go to purgatory.’ So too, “but know that for all these, God will bring you to judgment.”
Another matter: “Rejoice, young man, in your youth” – Rabbi Yudan and Rabbi Pinḥas: Rabbi Yudan said: “In your youth” – in your Torah that you studied in your youth. “Let your heart cheer you in the days of your youth” – this is the Mishna. “Walk in the ways of your heart” – this is the Talmud. “But know that for all these, God will bring you to judgment” – these are the mitzvot and good deeds.
Rabbi Pinḥas says: “Rejoice, young man, in your youth” – what caused you to be chosen in your old age? It is the Torah that you studied in your youth. If you were chosen in your old age, do not get carried away with matters of Torah,⁴²Do not get carried away in promulgating novel halakhic rulings. but rather, “walk in the ways of your heart” – this is the Talmud that you learned from your teachers. “But know that for all these….” He will pay you the reward for mitzvot and good deeds.
Rabbi Shimon ben Yoḥai says: [This is analogous] to one who would reject women⁴³He would reject women as marriage partners. and was steeped in promiscuity. He would say: ‘What woman whom I would want? Is this the woman I would want?’ He grew old and sought to marry a woman. They said to him: ‘Unlucky, unfortunate one, what woman would want you now that your nose runs, you are hard of hearing, and your eyesight is dim?’ So too, “but know that for all these, God will bring you to judgment.”
[This is analogous] to one who has fields and vineyards, but he did not separate teruma and tithes. He grew old and became impoverished. He said: ‘If I had fields and vineyards, would I not separate teruma and tithes?’ They said to him: ‘What was is in the past.’ So too, “but know that for all these, God will bring you to judgment.”