what was the nature of his righteousness - is righteousness a relative quality? Does it depend on context?
"These are the generations of Noah...[Noah was a righteous man, perfect in his generation]. Rabbi Yochanan said: "In his generation" he was considered righteous, but not in other generations. Reish Lakish said, "In his generation" and even the more so in other generations.
(א) וַיְהִי אַבְרָם בֶּן תִּשְׁעִים שָׁנָה וְתֵשַׁע שָׁנִים וַיֵּרָא יהוה אֶל אַבְרָם וַיֹּאמֶר אֵלָיו אֲנִי אֵל שַׁדַּי הִתְהַלֵּךְ לְפָנַי וֶהְיֵה תָמִים.
(1) And when Abram was ninety years old and nine, the Eternal appeared to Abram, and said unto him: ‘I am God Almighty; walk before Me, and be thou sincere.
(ה) וַיַּ֣רְא ה' כִּ֥י רַבָּ֛ה רָעַ֥ת הָאָדָ֖ם בָּאָ֑רֶץ וְכָל־יֵ֙צֶר֙ מַחְשְׁבֹ֣ת לִבּ֔וֹ רַ֥ק רַ֖ע כָּל־הַיּֽוֹם׃ (ו) וַיִּנָּ֣חֶם ה' כִּֽי־עָשָׂ֥ה אֶת־הָֽאָדָ֖ם בָּאָ֑רֶץ וַיִּתְעַצֵּ֖ב אֶל־לִבּֽוֹ׃ (ז) וַיֹּ֣אמֶר ה' אֶמְחֶ֨ה אֶת־הָאָדָ֤ם אֲשֶׁר־בָּרָ֙אתִי֙ מֵעַל֙ פְּנֵ֣י הָֽאֲדָמָ֔ה מֵֽאָדָם֙ עַד־בְּהֵמָ֔ה עַד־רֶ֖מֶשׂ וְעַד־ע֣וֹף הַשָּׁמָ֑יִם כִּ֥י נִחַ֖מְתִּי כִּ֥י עֲשִׂיתִֽם׃
(5) And the Eternal saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually. (6) And God repented that He had made man on the earth, and it grieved Him at His heart. (7) And God said: ‘I will blot out the human being whom I have created from the face of the earth; both human, and beast, and creeping thing, and fowl of the air; for I repent that I have made them.’
(13) And God said to Noah: ‘The end of all flesh is come before Me; for the earth is filled with violence through them; and, behold, I will destroy them with the earth. (14) Make thee an ark of gopher wood; with rooms shalt thou make the ark, and shalt pitch it within and without with pitch. (15) And this is how thou shalt make it: the length of the ark three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits. (16) A light shalt thou make to the ark, and to a cubit shalt thou finish it upward; and the door of the ark shalt thou set in the side thereof; with lower, second, and third stories shalt thou make it. (17) And I, behold, I do bring the flood of waters upon the earth, to destroy all flesh, wherein is the breath of life, from under heaven; every thing that is in the earth shall perish. (18) But I will establish My covenant with thee; and thou shalt come into the ark, thou, and thy sons, and thy wife, and thy sons’wives with thee. (19) And of every living thing of all flesh, two of every sort shalt thou bring into the ark, to keep them alive with thee; they shall be male and female. (20) Of the fowl after their kind, and of the cattle after their kind, of every creeping thing of the ground after its kind, two of every sort shall come unto thee, to keep them alive. (21) And take thou unto thee of all food that is eaten, and gather it to thee; and it shall be for food for thee, and for them.’ (22) Thus did Noah; according to all that God commanded him, so did he.
Why is Noah silent? What would be a good response to this detailed instruction?
(17) Now the Eternal had said, “Shall I hide from Abraham what I am about to do, (18) since Abraham is to become a great and populous nation and all the nations of the earth are to bless themselves by him? (19) For I have singled him out, that he may instruct his children and his posterity to keep the way of the Eternal by doing what is just and right, in order that the Eternal may bring about for Abraham what He has promised him.” (20) Then the Eternal said, “The outrage of Sodom and Gomorrah is so great, and their sin so grave! (21) I will go down to see whether they have acted altogether according to the outcry that has reached Me; if not, I will take note.”
Why is Abraham not silent? What would be a good response to God's information?
Why is the flood called "the waters of Noah"?
(9) For this is as the waters of Noach to Me; For as I have sworn that the waters of Noach should no more go over the earth, so have I sworn that I would not be get angry at you...
In Midrash Tanhuma on Parashat Noah we find a story that illustrates the weakness that some Rabbis saw in Noah’s character:
When Noah came out of the ark, he opened his eyes and saw the whole world completely destroyed. He began crying for the world and said, “God, how could you have done this?” ... God replied, “Oh Noah, how different you are from the way Abraham ... will be. He will argue with me on behalf of Sodom and Gomorrah when I tell him that I plan their destruction... But you, Noah, when I told you I would destroy the entire world, I lingered and delayed, so that you would speak on behalf of the world. But when you knew you would be safe in the ark, the evil of the world did not touch you. You thought of no one but your family. And now you complain?” Then Noah knew that he had sinned.
Zohar, Noah 67b
Once God told Noah that he and his family will be saved, he did not pray for the rest of the world, and it was destroyed. That is why the flood is named after him, as it is written (Isaiah 54:9):
"For this is to Me [as] the waters of Noah, as I swore that the waters of Noah shall never again pass over the earth…”
God learns that not everything goes to plan. And God removes the curse on the ground that had been placed at the time of Adam and Eve - Noah lives up to the aspiration of his name, that he will mitigate the itz'von, the hard and creative work, that human beings have to do since leaving Eden.
(כ) וַיִּ֥בֶן נֹ֛חַ מִזְבֵּ֖חַ לַֽה' וַיִּקַּ֞ח מִכֹּ֣ל ׀ הַבְּהֵמָ֣ה הַטְּהוֹרָ֗ה וּמִכֹּל֙ הָע֣וֹף הַטָּהֹ֔ר וַיַּ֥עַל עֹלֹ֖ת בַּמִּזְבֵּֽחַ׃ (כא) וַיָּ֣רַח ה' אֶת־רֵ֣יחַ הַנִּיחֹחַ֒ וַיֹּ֨אמֶר ה' אֶל־לִבּ֗וֹ לֹֽא־אֹ֠סִף לְקַלֵּ֨ל ע֤וֹד אֶת־הָֽאֲדָמָה֙ בַּעֲב֣וּר הָֽאָדָ֔ם כִּ֠י יֵ֣צֶר לֵ֧ב הָאָדָ֛ם רַ֖ע מִנְּעֻרָ֑יו וְלֹֽא־אֹסִ֥ף ע֛וֹד לְהַכּ֥וֹת אֶת־כָּל־חַ֖י כַּֽאֲשֶׁ֥ר עָשִֽׂיתִי׃
(20) And Noah built an altar to the Eternal; and took of every clean beast, and of every clean fowl, and offered burnt-offerings on the altar. (21) And the Eternal smelled the sweet savour; and the Eternal said in His heart: ‘I will not again curse the ground any more for man’s sake; for the imagination of man’s heart is evil from his youth; neither will I again smite any more every thing living, as I have done.
The waters of creation were divided between the waters above the earth and the waters below the earth. The waters of the flood were caused when that division was removed, allowing them to flow freely and cover the earth that had been uncovered when God had gathered the waters in order to create sea and dry land. The bow in the sky is a marker that the waters are now divided again, it never touches the ground but stays in the sky, held in place for all time
(יב) וַיֹּ֣אמֶר אֱלֹהִ֗ים זֹ֤את אֽוֹת־הַבְּרִית֙ אֲשֶׁר־אֲנִ֣י נֹתֵ֗ן בֵּינִי֙ וּבֵ֣ינֵיכֶ֔ם וּבֵ֛ין כָּל־נֶ֥פֶשׁ חַיָּ֖ה אֲשֶׁ֣ר אִתְּכֶ֑ם לְדֹרֹ֖ת עוֹלָֽם׃ (יג) אֶת־קַשְׁתִּ֕י נָתַ֖תִּי בֶּֽעָנָ֑ן וְהָֽיְתָה֙ לְא֣וֹת בְּרִ֔ית בֵּינִ֖י וּבֵ֥ין הָאָֽרֶץ׃
(12) And God said: ‘This is the token of the covenant which I make between Me and you and every living creature that is with you, for perpetual generations: (13) I have set My bow in the cloud, and it shall be for a token of a covenant between Me and the earth.
פרקי דרבי אליעזר (היגר " - ) חורב" פרק כב
...אמר להם נח שובו מדרכיכם וממעשיכם הרעים שלא יבא עליכם את מי המבול ויכרית כל זרע בני אדם ..
Pirke d'Rabbi Eliezer (Heger), 'Chorev' chapter 22, translation by Gideon Aronovich
Noah said to them [the people of his generation], return from your evil ways and deeds, in order that the waters of the flood may not come upon you and extinguish the progeny of man.