לֵ֤ב חָכָם֙ לִֽימִינ֔וֹ וְלֵ֥ב כְּסִ֖יל לִשְׂמֹאלֽוֹ׃
Serce mądrego zmierza ku prawicy jego, ale serce głupiego ku stronie jego lewej.
Or HaChaim
And you should not think that given that the soul is within man, or through involvement in Torah, with this he is still from the machinations of the impulse that brings him to sin and he [can] turn and walk [away from it]; because were it so, there would be no [room for] reward and punishment here. To this, it says that darkness is still in the world, but through [the light], man is helped to wage war with it, and to separate it from him, that it not fell him through its plots; and he will recognize that the aspect of doing evil is evil; and this is what it says, "and God separated between the light," which is the soul "and between the darkness," which is the evil impulse; and [about] this, the verse states (Ecclesiastes 10:2), "The heart of a wise man is to his right," which is the place of light, the place of the soul, "and the heart of a fool is to his left," which is the place of the evil impulse; "And He called light, day, and darkness, He called night;" and for this David prayed (Psalms 91:5), that He should save him from the fear of the 'nights.'
Rabbeinu Bahya
A Midrashic approach based on Tanchuma Mattot 5: when material wealth is received from heaven it is liable to endure; if its source is not heavenly it is unlikely to endure. There were two truly wealthy people in the world, one was an Israelite, i.e. Korach, the other was Haman. Both of them not only lost their wealth but they perished ignominiously seeing that their material wealth had not been a gift from heaven. They had acquired it by tearing it away from others.
You will also find that the wealth possessed by the members of the tribes Gad and Reuven caused them to become inordinately fond of it. As a result they lived (loosely speaking) in what we call חוצה לארץ, outside the essential part of Eretz Yisrael. They separated from the main body of the people on account of their possessions and wound up being the first to be exiled because of their sins (compare Chronicles I 5,26).
When we read in Psalms 75,7: “for what lifts a man comes not from the east or the west or the wilderness הרים, for it is G’d Who gives judgment, He brings down one man, He lifts up another.” The psalmist referred to the fate of the two and a half tribes Reuven, Gad, and half of Menashe (compare Tanchuma Mattot 6). The words ולא ממדבר הרים, normally translated as “and not from a wilderness of mountains,” are somewhat misleading. Whereas it is true that everywhere else in the Holy Bible the word הרים means “mountains,” in this instance it means “elevation.” (socially, financially). When G’d wanted to enrich the members of these tribes He gave them what had belonged to the Midianites. Thereby He fulfilled what is written in Psalms 75,7.
Why are material possesions called נכסים ? Because it is in the nature of such belongings to be hidden (disappear) from one owner and become revealed to the other owner. Chanah alluded to this when she said in Samuel I 2,7: ה' מוריש ומעשיר, משפיל אף מרומם, “the Lord makes poor and makes rich; He casts down, He also lifts high.” When G’d displays His anger (אף) at one people, another is liable to benefit from that. This is the reason our chapter is introduced most unusually with the conjunctive letter ו. Instead of the words ומקנה רב היה, וגו', I would have expected something like לבני ראובן וגד היה מקנה רב. The letter ו as the introduction to the whole chapter draws our attention to the fact that the reason these tribes had so many possessions was only because they had captured them from the Midianites, i.e. that G’d had deprived the Midianites of their possessions.
When Kohelet 10,2 speaks of “the heart of the wise being on the right whereas the heart of the foolish is on the left,” he had in mind people like the members of the tribes of Gad and Reuven who made things of secondary significance such as the livestock their primary concern, i.e. they confused that which is essential with that which is merely auxiliary. They demonstrated this when they mentioned their livestock before referring to their children (verse 16). G’d told them that people who considered their personal wealth as more important than their children would find that their wealth was not blessed. This is what Solomon taught us in Proverbs 20,21: “An inheritance gained hastily (sudden riches) at the outset will not be blessed in the end.” This is also the meaning of Proverbs 23,4: “Do not tire yourself out trying to become rich; desist out of a feeling of insight.” The truly wealthy individual is he who is content with what G’d has seen fit to provide for him as we know from Psalms 128,2: “when you consume the fruit of the labors of your hands you will be happy and feel content.”
You will also find that the wealth possessed by the members of the tribes Gad and Reuven caused them to become inordinately fond of it. As a result they lived (loosely speaking) in what we call חוצה לארץ, outside the essential part of Eretz Yisrael. They separated from the main body of the people on account of their possessions and wound up being the first to be exiled because of their sins (compare Chronicles I 5,26).
When we read in Psalms 75,7: “for what lifts a man comes not from the east or the west or the wilderness הרים, for it is G’d Who gives judgment, He brings down one man, He lifts up another.” The psalmist referred to the fate of the two and a half tribes Reuven, Gad, and half of Menashe (compare Tanchuma Mattot 6). The words ולא ממדבר הרים, normally translated as “and not from a wilderness of mountains,” are somewhat misleading. Whereas it is true that everywhere else in the Holy Bible the word הרים means “mountains,” in this instance it means “elevation.” (socially, financially). When G’d wanted to enrich the members of these tribes He gave them what had belonged to the Midianites. Thereby He fulfilled what is written in Psalms 75,7.
Why are material possesions called נכסים ? Because it is in the nature of such belongings to be hidden (disappear) from one owner and become revealed to the other owner. Chanah alluded to this when she said in Samuel I 2,7: ה' מוריש ומעשיר, משפיל אף מרומם, “the Lord makes poor and makes rich; He casts down, He also lifts high.” When G’d displays His anger (אף) at one people, another is liable to benefit from that. This is the reason our chapter is introduced most unusually with the conjunctive letter ו. Instead of the words ומקנה רב היה, וגו', I would have expected something like לבני ראובן וגד היה מקנה רב. The letter ו as the introduction to the whole chapter draws our attention to the fact that the reason these tribes had so many possessions was only because they had captured them from the Midianites, i.e. that G’d had deprived the Midianites of their possessions.
When Kohelet 10,2 speaks of “the heart of the wise being on the right whereas the heart of the foolish is on the left,” he had in mind people like the members of the tribes of Gad and Reuven who made things of secondary significance such as the livestock their primary concern, i.e. they confused that which is essential with that which is merely auxiliary. They demonstrated this when they mentioned their livestock before referring to their children (verse 16). G’d told them that people who considered their personal wealth as more important than their children would find that their wealth was not blessed. This is what Solomon taught us in Proverbs 20,21: “An inheritance gained hastily (sudden riches) at the outset will not be blessed in the end.” This is also the meaning of Proverbs 23,4: “Do not tire yourself out trying to become rich; desist out of a feeling of insight.” The truly wealthy individual is he who is content with what G’d has seen fit to provide for him as we know from Psalms 128,2: “when you consume the fruit of the labors of your hands you will be happy and feel content.”
Kli Yakar
And You from the myriads of holiness. Some say that He came from the myriads of holy angels who said, “A hidden treasure, You are coming to give to flesh and blood?” Nevertheless, the Holy One, blessed be He, came from them because they are holy and have no evil inclination, adultery, or theft. Therefore, because they are myriads of holiness, He came to Israel to complete their deficiencies and refine the rust of their material nature like gold refined in fire. For this reason it says, from His right hand a fiery law for them, in order to refine them so they do not turn to the left but to the right, for a wise man’s heart is at his right (Ecclesiastes 10:2).