“Forever, Lord, Your word stands firm in the heavens” (Psalms 119:89) – is this to imply that it is not so on earth? It means, rather, that what You said to Abraham in the heavens [stands firm]: “At the prescribed time, I will return to you; at this very time next year, [Sarah will have a son]” (Genesis 18:14). Rabbi Naḥman of Yafo in the name of Rabbi Yaakov of Caesarea began: “God of hosts, please return.
Look from heaven and see, and remember this vine” (Psalms 80:15) – return and perform what You said to Abraham: “Look now toward the heavens, and count the stars” (Genesis 15:5). “Remember this vine” – “the Lord remembered Sarah.”4The Psalmist was praying that God once again grant fertility and increase for Israel as He did for Abraham and Sarah. Rabbi Shmuel bar Naḥman began: “God is not a man, that He would lie, or the son of man, that He would reconsider” (Numbers 23:19).
Rabbi Shmuel said: This verse, its beginning does not correspond to its end, and its end does not correspond to its beginning. [The beginning states:] “God is not a man, that He would lie…[and the end states] He will say and not perform, speak and not fulfill” (Numbers 23:19). The explanation is that when the Holy One blessed be He decrees to bring something good upon the world, “God is not a man, that He would lie.”
But when he decrees to bring something detrimental, [sometimes] “He will say and not perform, speak and not fulfill.” When He said to Abraham: “For it is through Isaac that descendants will be considered for you” (Genesis 21:12) – “God is not a man, that He would lie.” But when He said to him: “Take now your son, your only one […and offer him up]” (Genesis 22:2) – “He will say and not perform.” When the Holy One blessed be He said to Moses: “I have remembered you [and what has been done to you in Egypt, and I said: I shall bring you up from the affliction of Egypt] (Exodus 3:16–17) – “God is not a man, that He would lie.”
When the Holy One blessed be He said to him: “Let Me be, and I shall destroy them” (Deuteronomy 9:14) – “He will say and not perform.” When the Holy One blessed be He said to Abraham: “And also that nation [whom they will serve, I shall judge]” (Genesis 15:14) – “God is not a man, that He would lie.” But when He said to him: “They will be enslaved to them and they will oppress them [four hundred years]” (Genesis 15:13) – “He will say and not perform.”5The period of subjugation in Egypt in fact lasted only two hundred and ten years.
When the Holy One blessed be He said to him [Abraham]: “I will surely return to you […and, behold, a son for Sarah your wife]” (Genesis 18:10) – “God is not a man, that He would lie.” Rather, “the Lord remembered Sarah.”