Genesis 6:7

And the Lord said, I will abolish by My Word man, whom I have created upon the face of the earth, from man to cattle, to the reptile, and to the fowl of the heavens; because I have repented in My Word that I have made them.

'ויאמר ה, G’d either said this to Himself, or to Noach.

אמחה את האדם אשר בראתי, the prefix ה before the word אדם is meant to tell us that G’d did not mean to wipe out the human species, אדם, but only האדם, seeing that some humans were allowed to survive. In supplying a rationale why the means used to wipe out all these people was the water, Rabbi Berechyah in Bereshit Rabbah 28,2 describes G’d as saying to Himself, that seeing He had made man out of earth, the only element (of the four that man is made of) which could neutralise earth is water. The words מאדם עד בהמה, included the free roaming beasts on earth, חיה, whereas the word רמש refers to the small creatures as we explained already on 1,25-26. Why were all these creatures wiped out also? What had they done to deserve this? They had only been created for the sake of man. If there was no purpose for man on earth, neither was there a purpose for all of these living creatures. Furthermore, seeing that the waters would cover the habitat of all these creatures they would die unless saved by a special miracle. The concern of G’d for all those creatures does not extend to each of them individually, but only to the survival of each of their species. G’d ensured that the species would survive by commanding Noach to take them into the ark with him, or at least to accept all those that came to the ark voluntarily, in pairs. If you were to ask why the deluge had to cover the entire surface of the earth and not only the areas inhabited by man, if G’d had done this, man could have escaped to uninhabited regions and survived thus foiling G’d’s plan. This is why even the highest mountains had to be covered by the waters to prevent anyone from escaping to the mountain peaks. Some of our sages (Sanhedrin 108) claim that the animals had become corrupt, copying man’s corrupt ways, so that they too deserved to die in their own right. They had become guilty of mating with species not their own, thus frustrating G’d’s plan that each species remain pure. Other sages (on the same folio) agree with the first opinion we offered, i.e. that in the absence of man on earth there was no purpose in the earth being populated by animals.

אמחה את האדם “I’ll dissolve the human species;” according to Rashi we must understand this as the human species consisting of earth and therefore subject to annihilation by water. G–d said that He would use water to bring about the dissolution of the human race. The expression used by the Torah according to Rashi to illustrate this is therefore מחוי, “dissolution,” instead of other words for destruction such as השמדה or כליה.