He said: When you deliver the Hebrew women and you look upon the birthstool [ovnayim], if it is a son you shall kill him but if it is a daughter she shall live (Exodus 1:16). “He said: When you deliver the Hebrew women…” Why did he command to kill them by means of the midwives? It was so the Holy One blessed be He would not prosecute him, but would punish them. “And you look upon the ovnayim,” [this is] the place through which the baby passes [as it emerges].
Alternatively, ovnayim, Rabbi Yehuda bar Simon said: The Holy One blessed be He makes a woman’s limbs hard as stones [avanim] when she is sitting on the birthstool in childbirth, as were it not so, she would die. Rabbi Pinḥas the ḥaver says in the name of Rabbi Yona, this supports Rabbi Yehuda bar Simon: Ovnayim means nothing other than a block, which is a hard object, as it is written: “I went down to the potter’s house, and behold, he was at work on the wheel [ovnayim]” (Jeremiah 18:3).30This is the surface on which the potter produces his vessel..
Rabbi Ḥanin said: He provided them a clear sign: Just as the potter has one thigh here and one thigh there and the block in the middle, so too, a woman giving birth has one thigh here and one thigh there and the newborn is in the middle. Some say: When she crouches to deliver, her thighs grow cold as stones. “If it is a son, you shall kill him.” He said to them, if it is male, kill him, and if it is female, do not kill her; rather, if she lives, she lives, and if she dies, she dies.
They said to him: How will we know if it is male or if it is female? Rabbi Ḥanina said: He provided them a clear sign. If it is face down, know that he is male, as he is looking, in his mother, at the earth from which he was created. If it is face up, she is a female, as she is looking at her source, the rib, as it is stated: “He took one of his ribs” (Genesis 2:21).
The Holy One blessed be He said to him: ‘Wicked one, whoever gave this counsel is a fool. You should have killed the females. If there are no females from where will the males marry women? One woman cannot take two men, but one man can take ten women, or one hundred.’ That is: “The princes of Tzoan are but fools” (Isaiah 19:11); it is they who gave him this counsel.