Midrash su Ecclesiaste 6:7

Another matter, “all the rivers,” all the Torah that a person studies is only in the heart. “Yet the sea is not full” – but the heart is not full and the soul is never sated, as it is stated: “But the soul is not filled” (Ecclesiastes 6:7). You might say that from the moment that a person expresses his learning to another, it will never return to him; the verse [therefore] states: “They go there again,” as it is written: “These matters that I am commanding you today shall be upon your heart” (Deuteronomy 6:6).
A certain noblewoman asked Rabbi Yosei bar Ḥalafta, she said to him: ‘What is that which is stated: “He granted wisdom to the wise [and knowledge to those with understanding” (Daniel 2:21)? The verse should have said: “He granted wisdom to the unwise, and knowledge to those without understanding.”’ He said to her a parable: ‘If two people come to you to borrow money from you, one of them wealthy and one of them poor, to which of them would you lend, to the wealthy one or the poor one?’ She said to him: ‘To the wealthy one.’ He said to her: ‘Why?’ She said to him: ‘Because if the wealthy man were to lose my money, he has [funds] with which to repay, but if the poor person were to lose my money, with what would he repay me?’ He said to her: ‘Don’t your ears hear what you utter with your mouth? Had the Holy One blessed be He granted wisdom to the foolish, they would be sitting and pontificating in its regard in bathrooms, theaters, and bathhouses. Rather, the Holy One blessed be He granted wisdom to the wise, and they sit and pontificate in its regard in synagogues and study halls. That is, “He granted wisdom to the wise, and knowledge to those with understanding.”’

(Lev. 19:23:) “When you come into the land.” Solomon said (in Prov. 31:16), “She sets her mind on a field and acquires it.” Come and see. Whatever Abraham thought about in his heart the Holy One, blessed be He, gave him. He thought [about] the land of [Israel], and He gave it to him, as stated (in Gen. 15:7), “I am the Lord who brought you out from Ur of the Chaldees [to give you this land as a possession].” Abraham said to the Holy One, blessed be He, “Master of the world, You have given me permission to speak in front of You, as stated (in vs. 8), “And he said, ‘Lord God, how shall I know that I shall possess it?” He replied and said to him (in vs. 13), “Know full well [that your seed shall be aliens in a land not theirs where they shall serve them and be oppressed by them].” Woe to that person who brings something out of his mouth without knowing how he brought it out. Because Abraham said (in vs. 8), “how shall I know,” He answered him, “Know fully well… they shall serve them and be oppressed by them for four hundred years.” One who speaks [like this] in front of any man is liable for his life; all the more so is he liable for his life if he speaks in front of the Holy One, blessed be He; he and his children and his children’s children until the end of all the generations [and] until the revival of the dead. It is not sufficient for these until the time of judgement, the time that a person’s soul withdraws from him. So did Solomon yell out (in Eccl. 6:7), “Is all human toil for one's mouth?” All the commandments and righteous deeds that one does; it is enough for the time that one's soul goes out of him. It is therefore stated (in Eccl. 6:7), “Is all human toil for one's mouth?” When Abraham heard from the Holy One, blessed be He, (in Gen. 15:13), “Know full well,” he thought about it in his heart and said, “Is it possible that every people which enslaves my children goes away in peace and is not condemned?” The Holy One, blessed be He, said to him (in Gen. 15:14), “But I am also judging the nation which they shall serve….” It is therefore stated (in Prov. 31:16), “She sets her mind on a field and acquires it.”

(Lev. 19:23:) WHEN YOU COME INTO THE LAND. Solomon said (in Prov. 31:16): SHE SETS HER MIND ON A FIELD AND ACQUIRES IT. Come and see.⁵²Tanh., Lev. 7:13. Whatever Abraham thought about in his heart the Holy One gave him. He thought [about] the land of [Israel], and he gave it to him, as stated (in Gen. 15:7): I AM THE LORD WHO BROUGHT YOU OUT FROM UR OF THE CHALDEES [TO GIVE YOU THIS LAND AS A POSSESSION]. Abraham said to the Holy One, Sovereign of the World, you have given me permission to say to you (in vs. 8): HOW SHALL I KNOW < THAT I SHALL POSSESS IT >? He replied and said to him (in vs. 13): KNOW FULL WELL < THAT YOUR SEED SHALL BE ALIEN IN A LAND NOT THEIRS WHERE THEY SHALL SERVE THEM AND BE OPPRESSED BY THEM >. Woe to that person who brings something out of his mouth without knowing how he brought it out. Because < Abraham > said (in vs. 8): HOW SHALL I KNOW? his children were condemned to be enslaved in Egypt for four hundred years. So Solomon said (in Eccl. 6:7): IS ALL HUMAN TOIL FOR ONE'S MOUTH…? What is the meaning of IS ALL HUMAN TOIL FOR ONE'S MOUTH…? All the commandments and righteous deeds that one does. It is enough for the time that one's soul goes out of him. It is therefore stated (in Eccl. 6:7): IS ALL HUMAN TOIL FOR ONE'S MOUTH? When Abraham heard < from the Holy One > (in Gen. 15:13): KNOW FULL WELL, he thought about it in his heart and said: < Is it possible >⁵³Both sets of bracketed words in the sentence occur in Codex Vaticanus Ebr. 34 and in the traditional Midrash Tanhuma (Jerusalem: Eshkol, n.d.), Lev. 7:23. that every people which enslaves my children goes away in peace and is not condemned? The Holy One said to him (in Gen. 15:14): BUT < I AM > ALSO < JUDGING > THE NATION < WHICH THEY SHALL SERVE >…. It is therefore stated (in Prov. 31:16): SHE SETS HER MIND ON A FIELD AND ACQUIRES IT.