Commentaire sur La Genèse 8:2

ויסכרו מעינות AND THE FOUNTAINS … WERE STOPPED –– When they were opened, it was stated that all fountains were opened (7:11), whilst here the word all is omitted: the reason is that such of them as were essential to the world were left unstopped, such as the hot springs of Tiberias and their like (Sanhedrin 108a).

ויסכדו מעינות תהום. The wells of the deep closed up. The Torah here hints that the waters beneath the earth had risen in proportion to the rain descending from the heavens. These two phenomena go hand in hand. Our verse alludes to this fact by mentioning the withdrawal of the waters beneath the earth as occurring simultaneously with the cessation of the rain from the heavens. We have pointed out previously that these two types of waters complement each other, enabling growth to occur (Taanit 28).

ויסכרו, they were shut, i.e. prevented from adding further turbulence on the surface of the waters which had flooded the globe. As a result of the wind blowing, the earth gradually began to dry out, the moisture being blown away, gradually. However, these subterranean wells were not all of them shut off. This enabled some of the waters on the surface of the globe to flow back gradually into the bowels of the earth from which they had come forth. While it is true that at the time these waters had risen to the surface they had found many more apertures through which to rise, and their appearance on the surface had been rapid, now it seeped back at a much slower pace.