פירוש על בראשית 7:18

ויגברו [AND THE WATERS] PREVAILED — by themselves (without any external aid).

AND THE WATERS PREVAILED (‘Vayigb’ru’). 19. AND THE WATERS ‘GAVRU’ (PREVAILED). This means that they increased exceedingly, for the Hebrew language calls great abundance gvurah (strength, power). So too, And their transgressions which ‘yithgavru’ (have prevailed),⁹⁰Job 36:9. meaning increased exceedingly; His mercy ‘gavar’ (has prevailed) toward them that fear Him,⁹¹Psalms 103:11. meaning increased. And so also: If ‘bigvuroth’ four-score years,⁹²Ibid., 90:10. meaning with great abundance.
It is conceivable that the meaning of vayigb’ru is that the rains came in a rushing downpour, uprooting trees and toppling buildings, since power is called in Hebrew gvurah (strength) because strength lies in power. In a similar sense are the verses: They also ‘gavru’ (wax mighty) in power;⁹³Job 21:7. ‘Vehigbir brith’ (And he shall make a strong covenant) with many for one week,⁹⁴Daniel 9:27. meaning he will establish the covenant with firmness. And in the words of the Sages, [we find the expression], gvuroth geshamim (the powers of the rains),⁹⁵Taanith 2a. because they come down with strength. It is possible that the verse, If ‘bigvuroth’ four-score years,⁹²Ibid., 90:10. is of the same sense, i.e., if his bones and body be strong, and he is a man of power, he will live four-score years. And if so, ‘gavru’ upon the earth⁹⁶Verse 19. will mean that the waters were in their complete strength, overcoming even the high mountains and inundating them.

ויגברו המים, this verse adds a new dimension to what we have been told already, i.e. that the waters became turbulent. This is why the Torah adds the word מאד מאד twice, something most unusual. The repeated statement וירבו, that the waters still kept increasing in volume, is meant to tell us that the waters did not only increase in turbulence but also kept increasing in quantity. Whereas originally, the waters could only raise the ark, now, thanks to the turbulence, the ark was driven in different directions from where it had stood originally.

ותלך התבה, not under its own power but by the pressure of the external waters.

By themselves. [Rashi knows this] because if they became powerful from the forty days of [rain of] the Flood, the order should be reversed and it should have written: “There was a Flood on the earth for forty days. The waters were powerful and increased greatly over the earth and lifted the ark, and it rose [high] above the earth, and the ark moved on the surface of the waters.” Rather, “The waters were powerful” was written at the end to teach that the [waters of the] deep rose “by themselves” and made the waters powerful. The Re”m explained differently: The rain stopped after forty days. And the water’s power could not have been during these forty days, for it is written (v. 24), “The waters were powerful over the earth for 150 days.” And it is not logical to say that the first “powerful” [mentioned in our verse] was from the rain, and the second “powerful prevailed” [of v. 24] was from the deep; [rather, the waters became powerful by themselves].