Genesis 7:6

And Noah was the son of six hundred years when the deluge of waters was upon the earth.

ונח, The Torah tells us how old Noach was when he entered the ark on account of the deluge that had begun. The letter ו in front of the word נח means the same as the word כאשר. We find parallel constructions of this use of the letter ו in Psalms 59,16 אם לא ישבעו וילינו, “when they are not satisfied they complain,” as well as in Psalms 63 7 ושפתי רננות יהלל פי, “I sing praises when my lips are joyful.” [clearly, one does not sing with one’s lips. Ed.]

והמבול היה מים, the word והמבול is used both as part of the previous part of the verse and as the end of the verse, i.e. “when the deluge which consisted of water took place, Noach was 600 years old.”

והמבול היה מים על הארץ, “when the deluge covered the earth with water.” There is good reason to ask why G–d chose the deluge as the instrument with which to punish mankind, rather than any other means at His disposal. Our sages in the Talmud tractate Rosh Hashanah folio 12 answered this question by stating that this method was chosen as it conformed to the principle of making the punishment match the sin. Man had sinned by means of boiling water, (metaphor for extremely serious sins, involving sexual emissions that are considered as the result of the body becoming heated) so G–d chose equally severe measures as the means to punish them by. The subject has been illustrated by a parable in which a king magnanimously set aside a section of a city to serve as residence for blind people, and he provided them with all comforts in order to make their lives more tolerable. Whenever the king passed this way, the blind people would rise and shout in gratitude for the king’s generosity. Once the king heard their voices and enquired from his entourage who was the source of this shouting. He was told that it originated with the blind people whom he so lavishly supported. They added that the blind people do the same whenever they hear horses galloping in their neighbourhood. He responded by saying: “how much louder would be their shouting if they were able to see their benefactor with their own eyes.” He therefore commanded to return these blind people to their former locations, and to install people with eyesight in the section formerly reserved for the blind. He ordered that the new residents be provided with all that he had formerly provided the blind with. When these people now realised that they had been promoted, they lived it up. Instead of being grateful, whenever the king passed in their area they raised their voices cursing him for having forced them to relocate. When the king was told about this, he decided to execute all these people.
The point of the parable is that originally the universe having been in chaos, was transformed into water, i.e. an element that is both blind and deaf. Even though, the waters praised the Lord for having thus raised their status. We know this from Psalms 93,3: נשאו נהרות ה', נשאו נהרות קולם, נשאו נהרות קולם, “the oceans sound o Lord, the oceans sound their thunder, the ocean sounds its pounding.” When the Lord heard this, He ordered the oceans which had covered the surface of the earth to be relocated so as to provide room for the earth to emerge and be seen. (Genesis 1.9) He created man in order to inhabit that earth, where previously there had only been water, providing man with fruit-bearing trees and all kinds of other luxuries, expecting, of course, to be rewarded with man’s expression of appreciation. The earth was so good that it required to be tilled only once in forty years. Instead, man took his good fortune for granted and instead of accepting the rules laid down by the Creator, rebelled against Him. When the Lord became aware of this, He had no choice but to punish them for their ingratitude. He commanded the waters to return to their original areas, allocated them at the beginning of creation. [The author credits his Rabbi with telling him this parable, who in turn had credited it to Rabbi Nathan Afniel.]