Midrash su Numeri 15:41

33 Another interpretation of (Numb. 21:17), "Then Israel sang": This is one of the three things that Moses said before the Holy One, blessed be He, and He said [back] to him, "You have taught me." He said in front of Him, "Master of the Universe, from where does Israel know what they did (was wrong)? Did they not grow up in Egypt? And all of Egypt are idolaters. And when You gave the Torah, You did not give it to them, and they were also not standing there, as it is stated (Exod. 20:18), 'And the people stood from afar.' And You only gave it to me, as it is stated (Exod. 24:1), 'And He said to Moses, "Ascend to the Lord.'" And when You gave the statements (Ten Commandments), You did not give [them] to them. You did not say, 'I am the Lord, your (plural) God'; but rather I am the Lord, your (singular) God. [Hence] You said it to me. Did I sin?" The Holy One, blessed be He, said to him, "By your life, you have spoken well. You have taught Me! From now on, I will say the expression, 'I am the Lord, your (plural) God.'" The second one is when the Holy One, blessed be He, said ( in Numb. 34:7), "visiting the iniquity of the parents upon the children": Moses said, "Master of the Universe, how many evildoers begat righteous ones; should they be removed by the iniquities of their parents? Terach was an idol-maker, but his son, Abraham, was righteous; so too Hezekiah was righteous, but Ahaz, his father was an evildoer; Josiah was righteous, but Amon, his father, was an evildoer. Is this proper, that the righteous be struck for the iniquities of their parents?" The Holy One, blessed be He, said to him, "Behold, you have taught Me! By your life, I will nullify My words and preserve your words, as it is stated (Deut. 24:15), ‘The parents shall not die for the children, and the children shall not die for the parents'; and it is by your life that I shall write [these things] in your name, as it is stated (II Kings 14:6), 'as it is written in the Torah of Moses, which God commanded ....'" The third one is when the Holy One, blessed be He, said to him, "Make war on Sichon; even if he does not want to engage with you, wage war with him, as stated (Deut. 2:24), 'Get up, go and cross the Arnon .'" But Moses did not do like this. Rather what is written above? "And I sent messengers" (Deut. 2:26). The Holy One, blessed be He, said to him, "By your life, I will nullify My words and preserve your words, as it is stated (Deut. 20:11), 'When you approach a town to attack it, you shall offer it terms of peace.'" Once Sichon did not accept, the Holy One, blessed be He, felled him in front of them, as it is stated (Deut. 20:33), "and we smote him." And not only that, but even [with] those that were hiding themselves in the caves to kill [the Israelites], the Holy One, blessed be He, signaled to the mountain and it crushed them, as it is stated (Ps. 74:13-14), "who smashed the heads of the monsters in the waters. It was You who crushed the heads of Leviathan." A common proverb says [that] if you gave bread to an infant, let his mother know. The Holy One, blessed be He, said, "From where will Israel know the favor I did for them?" What did He do? He distanced the mountains from each other and the streams swept down [the corpses], as it is stated (Numb 21:17), "And the streams poured." And the Israelites passed by and sang song - "then Israel sang" (Numb. 21:17). Israel said, "It is for You to do miracles for us, but it is for us to bless and laud Your name" - "Salvation is to the Lord; upon Your people is Your blessing, Selah" (Ps. 3:9). Upon the waters was it decreed against Moses, so he was not mentioned in the song. Moses said, "Master of the Universe, "I am dying because of them. You gave them the Torah from the wilderness, as it is stated, (Numb. 21:18), 'and from the wilderness, Matanah (which is also the word for gift).' And they possessed (nachalu) it from my hands, as it is stated (Numb. 21:19), 'And from Matanah, Nachliel.'" And from when they possessed it, You decreed death upon me, as it is stated (Numb. 21:19), "and from Nachliel, Bamot" - and from possession comes death (menachal, ba mot). "And from Bamot, Haggai in the field of Moav" (Numb. 21:20), as it is stated (Deut. 34:6), "And He buried him in the valley in the land of Moav." Job said, "He is not partial to princes; the noble are not preferred to the wretched; for all of them are the work of His hands" (Job 34:19).

R. Nathan said: There is no mitzvah in the Torah whose reward is not "at its side." Go and learn this from the mitzvah of tzitzith. There was once a certain man who was particularly diligent in the mitzvah of tzitzith. Once, hearing of a ("famed") harlot in the cities of the sea, who took four hundred gold coins as her hire, he sent her that sum, and she set a time for him. When the appointed time came, he went there and sat at the door of her house. Her maid-servant went in and said to her: That man whom you appointed a time for is sitting at the door of the house. The harlot: Let him come in. When he came in, she spread seven beds for him, six of silver and one of gold, and she was on the uppermost. Between each one was a silver ladder, and the uppermost, of gold. When he came to the act, his four tzitzith came and struck him across his face. They seemed to him like four men. He immediately left off and sat upon the ground. She, too, left off and sat upon the ground. She said to him "'Gapa of Rome' (an idolatrous oath), I shall not let you go until you tell me what blemish you have seen in me!" He: I swear, I have seen no blemish in you. There is no beauty like yours in all the world, but there is one mitzvah (tzitzith) concerning which it is written two times (Bamidbar 15:41) "I am the L-rd your G-d." "I am the L-rd your G-d" — I am destined to reward; "I am the L-rd your G-d" — I am destined to punish. And now they appeared to me as four witnesses (testifying to the above). At this, she said: I swear that I will not let you go until you write for me your name, the name of your city, and the name of the place where you study Torah. He wrote for her his name, the name of his city, the name of his master, and the name of the place where he studied Torah — whereupon she arose and divided all of her wealth: a third to the authorities (for permission to convert), a third to the poor, and a third which she took with her, in addition to those spreads. When she came to R. Meir's house of study, she said to him: My master, convert me. R. Meir: Is it possible that you have "cast your eyes" upon one of my disciples! At this, she took out the note that she had with her, and he said to her: "Go and claim your purchase!" Those spreads which she had spread for him unlawfully, she now spread for him lawfully, This was her reward in this world. As to the world to come, I do not know how much.