Midrasz do Wyjścia 1:7

Further said E. Jochanan in the name of R. Jose: "Every utterance which came forth from the mouth of the Holy One, praised be He! for good purpose even when upon condition, was never retracted." Whence do we derive this? From our Teacher Moses, as it is said (Deu. 9, 14.) Let me alone, and I may destroy them, and blot out their names from under the heavens, and I will make of thee a nation mightier and more numerous than they; and although Moses invoked mercy concerning this thing and succeeded in annuling that decree, yet it [the promise. And I will make thee a nation mightier and more numerous] was fulfilled to his children, as is said (I Chr. 23, 15-16.) The sons of Moses were Gershon, and Eliezer, and the sons of Eliezer were Rechabyah, the chief, the sons of Rechabyah became exceedingly great in number, and R. Joseph taught they were more than sixty myriads. This is inferred from the two similar words, Rabu, Rabu: It is written here. They were exceedingly great in number (Rabu), and it is written there (Ex. 1, 7.) They were fruitful and exceedingly great in number (Vayirbu).

Another interpretation (of Exod. 1:7): AND THE LAND WAS FILLED WITH THEM. Since the theater²⁹Gk.: theatra houses and the circus³⁰Lat.: circi; Gk.: kirka. houses were filled with them; <The Egyptians > immediately decreed that they (the Israelites) should withdraw from the bed. So it was stated (ibid.): AND THE LAND WAS FILLED WITH THEM.

Our sages said: They bore twins. Others say: Six were formed in a single womb. Others say: twelve were born from one womb. And still other contend six hudred thousand. Those who believed that twins were born explained it by the words: Were fruitful and increased abundantly (Exod. 1:7). Those who contended that six were born based it on the words: Were fruitful and increased abundantly, and multiplied, and waxed exceedingly mighty (ibid.), that is, six. Those who say that twelve were born argue that the words in this verse are in plural form, thus making twelve in all. Those who said six hundred thousand did so because it is written about fishes: Let the waters swarm abundantly (Gen. 1:20), and here it is written: Increased abundantly.