Midrash su Ecclesiaste 4:4

Rabbi Nahman said in Rabbi Samuel's name: 'Behold, it was good' refers to the Good Desire; 'And behold, it was very good' refers to the Evil Desire. (It only says 'very good' after man was created with both the good and bad inclinations, in all other cases it only says 'and God saw that it was good') Can then the Evil Desire be very good? That would be extraordinary! But without the Evil Desire, however, no man would build a house, take a wife and beget children; and thus said Solomon: 'Again, I considered all labour and all excelling in work, that it is a man's rivalry with his neighbor.' (Ecclesiastes 4:4).

Another matter, “He made everything beautiful in its time” – Rabbi Berekhya said that Rabbi Abbahu said in the name of Rabbi Elazar: The schism that was between Reḥavam and Yerovam was fitting to have been between David and Sheva ben Bikhri, but the Holy One blessed be He said: The Temple has not yet been constructed and I am introducing a schism in the kingdom of the House of David? Rather, let the Temple be constructed and then, what will ultimately happen, will happen.
Rabbi Binyamin said in the name of Rabbi Levi: “The world, too, He has placed in their heart” (Ecclesiastes 3:11) – He placed in their heart love of the world. Rabbi Yonatan said: He has placed in their heart fear of the angel of death. Neḥemya, son of Rabbi Shmuel bar Naḥman, said: “And behold it was very good” (Genesis 1:31). “And behold it was...good,” this is man; “and behold it was…good,” this is the good inclination, “very,” this is the evil inclination. Is the evil inclination “very good”? It is to teach you that were it not for the evil inclination, man would not build a house, would not marry a wife, and would not beget children, as Solomon says: “[I saw all toil and all skilled action;] that it is man’s envy of his neighbor” (Ecclesiastes 4:4).
Rabbi Berekhya and Rabbi Abbahu said in the name of Rabbi Yoḥanan: “The world, too, He has placed in their heart” – He placed in their heart love of the world, He placed in their heart love of young children. To what is this matter analogous? [It is analogous] to a king who had two sons, one big and one small. The big one cleans and the small one sullies; nevertheless, he loves the small one more than the big one.
Rabbi Aḥva son of Rabbi Zeira said: “The world [ha’olam],” the ineffable name was concealed [ho’olam] from them.⁴⁷The word ha’olam is written in the verse without the vav such that it can be read ho’olam. This is analogous to a king who made a feast [and] invited guests. Once they ate and drank, they said to him: ‘Give us swords and spears and we will play with them.’ He gave them myrtle branches and they struck each other and wounded each other. The king said to them: ‘If, when I gave you myrtle branches, this is what you did, had I given you swords and spears, all the more so.’ So too, the Holy One blessed be He said: ‘If, at a time when I concealed the ineffable name from them, they killed with appellations,⁴⁸By invoking names of God in cursing other people. had I given and revealed to them the ineffable name, all the more so.’ There was a Persian woman who cursed her son with one element of the ineffable name. Shmuel heard her and said: ‘Go prepare a shroud for him.’
Rabbi Ḥanina had knowledge of the ineffable name. When his death approached, he said: ‘Is there a person here to whom I can entrust it?’ They said: ‘Eneini bar Naḥshon is here.’ He sent for him and he came, and his own son entered and hid under the bed. When he was about to transmit it, that child sneezed. His father [Rabbi Ḥanina] said: ‘Go out of here. You are not worthy to hear it, and this one is not worthy to receive it.’⁴⁹Rabbi Ḥanina said to his son that he must leave because he is not worthy to hear it, and he also took this as a sign that he should not reveal the name to Eneini (Etz Yosef).
One doctor in Tzippori had knowledge of the ineffable name. When his death approached, he said: ‘Is there a person here to whom I can entrust it?’ They said: ‘Pinḥas bar Ḥama is here.’ He sent for him and he came. [The doctor] asked him [a question] and said to him: ‘Have you ever taken anything from a Jew?’ He said to him: ‘I have taken first tithe.’ [The doctor] resolved not to entrust it to him, saying: ‘Perhaps he will demand something from a person and he will not give it to him, and he will become angry with him and kill him.’ It is taught, one does not entrust the name to just any person, and not to one who has lived half his life, but rather, to one who has lived most of his life. In addition, one entrusts it only standing, and one entrusts it only in a place of purity, and near water. Initially, they would entrust it to any person. When the sinners became more prevalent, they instituted that it should be entrusted only to the modest among the priests, and the modest among the priests would obscure it in the melody of the priests.
Rabbi Tarfon said: One time I ascended to the platform with Samson, my mother’s brother, and I cocked my ear in the direction of the High Priest, but he obscured it in the melody of the priests. And Rabbi Tarfon said: One time I heard it and I fell on my face. Those nearby, when they hear it, fall on their faces and say: “Blessed be the name of His glorious kingdom for ever and ever.” These and those⁵⁰Those nearby and those farther away would not move from there until the time when it was forgotten [shenitalem] from them, as it is stated: “This is My name forever [le’olam]” (Exodus 3:15), le’elem is written.⁵¹It is written without a vav, such that it can be read le’elem, meaning for concealment. To what purpose? “But so that man will not discover the work that God has performed from beginning to end” (Ecclesiastes 3:11).⁵²This is to prevent people from discovering the secrets of Creation.