In Parshas Noach, we learn of a world that is completely corrupt, save for one righteous man, Noach. The Torah tells us that נֹחַ-הִתְהַלְֶּ ,הָאֱלֹקִים-אֶת בְּדֹרֹתָיו הָיָה תָּמִים צַדִּיק אִישׁ נֹחַ, Noach was a righteous man, he was pure in his generation, Noach walked with G-d (Bereishis 6:9).
While there are those who say that while in his generation he was righteous, had he been in the generation of Avraham he would have been considered as nothing; there are rabbis who say that he was a complete tzadik and had he been in a generation of tzadikim he would have been even more righteous! (Rashi, ibid).
In a time of immorality, idolatry, and thievery (Rashi to 6:11), the predominant sins of the time, Noach was a pure man. G-d himself proclaims to Noach that he and his family are worthy of being saved because: הַזֶּֽה בַּדּ֥וֹר לְפָנַ֖י צַדִּ֥יק רָאִ֛יתִי כִּֽי־אֹתְָ֥, for you I have seen a righteous man before Me in this generation (7:1).
In order for G-d to save Noach, his wife Naama (Rashi to 4:22), their three sons, Shem, Cham and Yafes, and the wives of their sons, G-d commands Noach to build an ark. The ark is to have three floors: one for the people, one for the animals that would also be saved, and one for the garbage. Into this ark all those who would be saved would enter, and would remain there all the while that the flood waters inundated the earth, and for the duration of time until the waters fully subsided.
However, G-d, Who is Omnipotent, would have many ways of saving Noach and his family. Why did He command Noach to build an ark - for one hundred and twenty year, no less!?
Rashi asks this question and explains as follows:
,שָׁנָה כ"ק בָּהּ עוֹסֵק הַמַּבּוּל דוֹר אַנְשֵׁי שֶׁיִּרְאוּהוּ כְּדֵי ?זֶה בְּבִנְיָן הִטְרִיחוֹ וְלָמָּה ,לְפָנָיו וְהַצָּלָה רֶוַח הַרְבֵּה יָשׁוּבוּ אוּלַי ,לָעוֹלָם מַבּוּל לְהָבִיא ה"הַקָּבָּ עָתִיד לָהֶם אוֹמֵר וְהוּא ,לְָ זֹּאת מַה אוֹתוֹ וְשׁוֹאֲלִין
There are many ways for G-d to bring about salvation and deliverance (when He wants to save someone). So why did He bother Noach with this construction? So that the people of the generation of the deluge would see Noach busy with ark-building for one hundred and twenty years, and they would inquire of him, ‘What are you making for yourself?’ and he would answer them and say: ’In the future, G-d will bring a deluge upon the earth (hence I am building an ark to save myself)’. Perhaps, upon hearing this, the people would repent (and the generation would be saved from destruction) (Rashi to 6:14).
Noach’s ark-building affects no one in his generation, and due to a complete lack of repentance, the entire world is destroyed in the mabul. מֵאָדָם ,הָאֲדָמָה פְּנֵי-עַל אֲשֶׁר הַיְקוּם-כָּל-אֶת וַיִּמַח בַּתֵּבָה ,אִתּוֹ וַאֲשֶׁר נֹחַ-אְַ וַיִּשָּׁאֶר ;הָאָרֶץ-מִן וַיִּמָּחוּ ,הַשָּׁמַיִם עוֹף-וְעַד רֶמֶשׂ-עַד בְּהֵמָה-עַד - And Hashem erased all existence from the face of the earth, from man to animal, to crawling things, to the birds of the heavens, and He erased them all from the land, and only Noach and that with him in the ark remained (7:23).
