“The Lord remembered Sarah” – Rabbi Yitzḥak said: It is written [regarding an unfaithful wife]: “If the woman was not defiled, and is untainted, she will be absolved, and will conceive offspring” (Numbers 5:28). This one, who entered Pharaoh’s palace and Avimelekh’s palace and emerged untainted, is it not all the more logical that she should be remembered?16By being granted the ability to conceive.
Rabbi Yehuda ben Rabbi Simon said: Although Rabbi Huna said it is an angel that is in charge of desire [and procreation], Sarah did not require such things, but rather, it was He Himself in His glory – “the Lord remembered Sarah.” “Sarah conceived, and bore Abraham a son in his old age, at the appointed time that God had spoken to him” (Genesis 21:2). “Sarah conceived, and bore Abraham a son in his old age” – it teaches that she did not steal semen from some other place [to impregnate herself].
“A son in his old age [zekunav]” – this teaches that his [Isaac’s] facial features [ziv ikonin] were similar to his. “At the appointed time [moed] that God had spoken to him” – Rabbi Yudan and Rabbi Ḥama, Rabbi Yudan said: He was born at nine months [of pregnancy],17The pregnancy began a number of days after she had left Avimelekh. Nine months is “the appointed time that God had spoken” when setting up the laws of nature. so people should not say that he was scooped out of Avimelekh’s palace.18People would not say that Avimelekh had fathered Isaac during that night when Sarah was with him.
Rabbi Ḥama said: At seven months [of pregnancy],19There was no need to negate Avimelekh’s paternity, because of Isaac’s strong resemblance to Abraham. which are nine incomplete ones.20One day at the end of one month, followed by seven full months, plus the first day of the next month adds up to seven months plus two partial months – nine months, counting partial months. A woman who gives birth after seven months of gestation is thus also, in a way, fulfilling God’s decree of nature that gestation should be nine months.
Rabbi Huna in the name of Rabbi Ḥizkiya: He was born at noon. Moed is stated here and it is stated elsewhere: “]You shall slaughter the Passover offering] as the sun begins to set,21The time of the slaughtering of the Passover offering is at noon., which is the time at which the sun begins its descent from its highest point in the sky. the appointed time [mo’ed] of your exodus from Egypt” (Deuteronomy 16:6).