Midrasz do Izajasza 54:9

(Exodus 18:1) "And Yithro heard": What did he hear that caused him to come (and join Israel)? The war with Amalek, which is juxtaposed with this section. These are the words of R. Yehoshua. He heard of the (prospective) giving of the Torah and he came. For when the Torah was to be given to Israel, all the kings of the earth shook in their palaces, viz. (Psalms 29:9) "and (each king) in his palace accorded glory" (to the L rd). At that time, all the kings of the nations convened with the wicked Bilam and said to him: Is it possible that He is going to do to us as He did to the generation of the flood? He replied: Fools that you are! The Holy One Blessed be He already swore to Noach that he would not bring (another) flood to the world, viz. (Isaiah 54:9) "For this to Me is like the waters of Noach, of which I swore that the waters of Noach would no more pass over the earth." They: Perhaps he will not bring a flood of water, but He will bring a flood of fire? Bilam: He will bring neither a flood of fire nor a flood of water, but the Holy One Blessed be He is giving Torah to His people and to His loved ones, viz. (Psalms, Ibid. 10) "the L rd will give strength ("oz" = Torah) to His people." When all of them heard this from his mouth, they all responded (Ibid.) "May the L rd bless His people with peace," and they turned and went, each to his place. R. Eliezer says: Yithro heard the splitting of the sea and came (to join Israel). For the splitting of the sea was heard from one end of the world to the other, viz. (Joshua 5:1) "And it was, when all the kings of the Emori heard, etc." And thus did Rachav the harlot say to the messengers of Joshua (Ibid. 2:10-11) "For we heard how the L rd dried up the waters of the Red Sea before you when you went out of Egypt … and when we heard, our hearts melted, and no spirit was left in a man before you." They said: Rachav the harlot was ten years old when Israel left Egypt, and all forty years that Israel was in the desert, she plied her trade. At the end of fifty years, she converted, saying: L rd of the universe, I have sinned in three areas: niddah, challah, and candle lighting. Forgive me by virtue of three things: the rope, the window, and the wall, viz. (Ibid. 15) "And she let them down by a rope through the window, for her house was on the side of the wall, and she lived within the wall."...

Rabba b. b. Chana said again: "The merchant said to me: 'Come and I will show you the mountain of Sinai.' I followed him, and saw that it was surrounded by serpents. All of them were standing, and looked like white asses. I also heard a Heavenly voice, saying: 'Woe is me that I have sworn; and now after having so done, who will absolve me from that oath? When I told this before the Rabbis, they said again: 'Abba himself is an ass, and b. b. Chana is a fool. Why didst thou not say: Thou art absolved, thou art absolved?'" He, however, did not do so, because he thought: Perhaps it means the oath against the flood, in reference to which it is written (Is. 54, 9) As I have, sworn that the waters of Noah, etc. The Rabbis, however, were right in accusing him, as if it were about the flood, why then, woe is me?

“Return us to You, Lord, and we will return; renew our days as of old” (Lamentations 5:21).
“Return us to You, Lord, and we will return.” The congregation of Israel said before the Holy One blessed be He: ‘Master of the universe, it is incumbent upon You to return us.’ He said to them: ‘It is incumbent upon you, as it is stated: “Return to Me and I will return to you, said the Lord” (Malachi 3:7).’ It said before Him: ‘Master of the universe, it is incumbent upon you, as it is stated: “Return us, God of our salvation” (Psalms 85:5).’ That is why it is stated: “Return us to You, Lord, and we will return.”
“Renew our days as of old [kekedem].” Like Adam the first man, just as it says: “He banished the man; He stationed…east [mikedem] of the Garden of Eden” (Genesis 3:24).²⁸Adam repented after being banished from Eden, and his repentance was accepted (Rabbi David Luria). Alternatively, “renew our days as of old.” Just as it says: “The offering of Judah and Jerusalem will be pleasant to the Lord, as in the days of old and as in former years” (Malachi 3:4). “As in the days of old,” this is Moses, as it is written: “He remembered the days of old, Moses, His people” (Isaiah 63:11). “And as in former years,” like the years of Solomon. Rabbi [Yehuda HaNasi] says: “As in the days [kimei] of old,” as in the days of Noah, as it is stated: “For, like the waters of [ki mei] Noah, this is for Me” (Isaiah 54:9). “And as in former years,” like the years of Abel, when there was not yet idolatry in the world.