“Fashion an Ark” (6:14)
The Ohr HaChaim HaKadosh teaches that this command can be explained by the pasuk in Yechezkel 14:14: “Now should these three men be in its midst: [namely] Noach, Daniel and Iyov; they will save themselves with their righteousness, says the L-rd G-d.” Three have the power to save themselves from evil, whereas only two – and obviously just one – cannot prevent themselves from destruction... This is why Noach was commanded by HaSehm to build “himself” a teiva, because he was not righteous enough to be saved on his own merits. Clearly his sons were also not as righteous as he was, since together they were more than three and, had they been sufficiently righteous, they would have been saved from destruction.
In the previous pasuk the Ohr HaChaim HaKadosh cited Chazal (Medrash Bereishis Rabba 49), that Avrohom Avinu only asked HaSehm to prevent the destruction of Sedom if there were ten Tzaddikim, and that he learned this from Noach, who did not daven that the world be saved because there were fewer than ten Tzaddikim. However, this idea is difficult to understand, because Noach was alone in his generation (and how could Avrohom learn this from Noach when their situations were not the same)! The answer seems to be that once the angel of destruction was unleashed into the world, they were required to be as righteous as Noach – or more so – in order to prevent their own deaths and save themselves. Had Noach davened to prevent the destruction before the forces of evil were unleashed, he would have succeeded. Although others in the world were not as righteous as him, their righteousness was sufficient to save others before the destruction was unleashed. Once it was unleashed, however, only Tzaddikim of an equal stature to Noach could have stopped it and saved even just themselves. But Noach was alone.
This is why the pasuk in Yechezkel names three specific Tzaddikim: Noach, Daniel and Iyov, rather than counting any three Tzaddikim, because once permission is granted for the forces of evil and destruction to begin, only those of similar stature can succeed in saving others.
