Midrasz do Rodzaju 17:17

THE GATHERING OF THE WATERS
ON the third day all the earth was flat like a plain and the waters covered the surface of all the earth. When the word of the Almighty was uttered, "Let the waters be gathered together" (Gen. 1:9), the mountains and hills arose from the ends of the earth and they were scattered over the surface of all the earth, and valleys were formed over the inner parts of the earth; and the waters were rolled together and gathered into the valleys, as it is said, "And the gathering together of the waters he called seas" (Gen. 1:10). Forthwith the waters became proud and they arose to cover the earth as at first, when the Holy One, blessed be He, rebuked them || and subdued them, and placed them beneath the soles of His feet, and measured them with the hollow of His hand that they should neither decrease nor increase. He made the sand as the boundary of the sea, just like a man who makes a fence for his vineyard. When they rise and see the sand before them they return to their former place, as it is said, "Fear ye not me? saith the Lord: will ye not tremble at my presence, which have placed the sand for the bound of the sea?" (Jer. 5:22).

Rabban Gamaliel, the son of Rabbi Jehudah the Prince, said: When our father Abraham was circumcised, on the third day he was very sore, in order to test him. What did the Holy One, blessed be He, do? He pierced one hole in the midst of Gehinnom, and He made the day hot, like the day of the wicked. He went forth, and sat down at the entrance of the tent in the cool of the day, as it is said, "And he sat at the tent door (in the heat of the day)" (Gen. 18:1). The Holy One, blessed be He, said to the ministering angels: Come ye, let us descend and visit the sick, for the virtue of visiting the sick is great before Me. The Holy One, blessed be He, and the angels descended to visit our father Abraham, as it is said, "And the Lord appeared unto him" (ibid.). The Holy One, blessed be He, said to the ministering angels: Come ye and see ye the power of circumcision. Before Abraham was circumcised he fell on his face (before Me), and afterwards I spake with him, as it is said, "And Abraham fell upon his face" (Gen. 17:17). Now that he is circumcised he sits and I stand. Whence do we know that the Holy One, blessed be He, was standing? Because it is said, "And he looked, and, lo, three men stood over against him" (Gen. 18:2).

How do we know (this with reference to) Isaac? Because it is said, "And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac" (Gen. 17:19). Why was his name called Isaac? Because Yad (the first Hebrew letter of Isaac indicates) the ten trials wherewith our father Abraham was tried; and he withstood them all. Zaddi (the second letter indicates) the ninety (years), for his mother was ninety years (at the birth of Isaac), as it is said, "And shall Sarah, that is ninety years old, bear?" (Gen. 17:17). Cheth (the third letter points to) the eighth (day), for he was circumcised on the eighth day, as it is said, "And Abraham circumcised his son Isaac, being eight days old" (Gen. 21:4). Ḳuf (the fourth letter of the name marks) the hundred (years), for his father was an hundred years old (at Isaac's birth), as it is said, "And Abraham was an hundred years old" (Gen. 21:5).

The second wonder (was) about the wives of the sons of Noah. From the day when the heavens and the earth were created there never was a woman who at ninety years of age had a child, until Sarah came and bare (a son) when (she was) ninety years old. All the kings of the earth heard (thereof), and they did not believe. What did the Holy One, blessed be He, do to them? He dried up the breasts of their wives, as it is said, "And all the trees of the field shall know that I the Lord have brought down the high tree, have exalted the low tree, have dried up the green tree, and have made the dry tree to flourish" (Ezek. 17:24).