Every Bible student knows that Isaac was Jacob’s father. According to Genesis 25:21-26, Rebekah conceives twins, and Jacob’s birth follows (literally) on the heels of Esau. Yet, three chapters later, God tells Jacob, “I am the Lord, the God of Abraham your father (אברהם אביך; Avraham avikha), and the God of Isaac” (28:13). God specifies Abraham as Jacob’s father, but not Isaac. This divine shift in patrilineal terminology occurs before God gives Jacob the same covenant promises that Abram had received at his calling. By referring to Abraham as Jacob’s father, the Lord reiterates the guarantee that the nation inaugurated with Abram would become a blessing to the whole world.
According to Genesis, “Isaac loved Esau because he ate of his game, but Rebekah loved Jacob” (25:28). These parental preferences lead to a filial dichotomy when Jacob steals Esau’s blessing. In Genesis 27, Isaac calls Esau “my son” (בני; beni) twice (27:1, 37), and a further seven times when he thinks that the disguised Jacob is Esau (27:20-21, 24-27). Rachel calls Jacob “my son” three times (27:8, 13, 43), but neither parent addresses their respective filial counterparts in this way. Thus, Genesis underscores Isaac’s preference for Esau and Rebekah’s loyalty to Jacob. The one exception appears just before Jacob deceives his father. Not knowing which of his offspring is before him, Isaac asks, “Who are you, my son (בני; beni)?”; Jacob replies, “I am Esau your firstborn” (27:18-19). In the moment before deception, Scripture reminds the reader that, despite Isaac’s fondness for Esau, sonship belongs to both children. Still, Jacob’s trickery impacts his father deeply—when he realizes the ruse “Isaac tremble[s] a great trembling” (ויחרד יצחק חרדה גדלה; vayeherad Yitshaq haradah gedolah; 27:33). Jacob secures Isaac’s blessing, but Scripture says that the quality of the father-son relationship remained ambiguous until “Isaac sent Jacob away” (28:5).
After Jacob leaves his father, he has a visionary dream of God atop a heavenly “staircase” (סלם; sulam; Gen 28:12). The deity declares, “I am the Lord, the God of Abraham your father, and the God of Isaac. The land on which you lie I will give to you and to your offspring (לך אתננה ולזרעך; lekha etnenah u’lezarekha). Your offspring shall be like the dust of the earth (כעפר הארץ; k’afar ha’arets)… and in you all the families of the earth will be blessed (נברכו בך כל משׁפחת האדמה; nivrakhu vekha kol mishpehot hadamah).” (28:13). The divine promise to Jacob echoes what God had said to Abraham, and then reiterated to Isaac. To Abram, God proclaims, “In you all the families of the earth will be blessed…. To your offspring I will give this land…. I will make your offspring like the dust of the earth” (Gen 12:3, 7; 13:16; cf. 15:7, 18; 26:2-4). In the broader context of Genesis, God refers to Abraham as Jacob’s “father” (אב; av) to show that, despite the rocky relationship between Isaac and Jacob, there is also a direct patrilineal link between Jacob and his grandfather—Jacob is just as much a “son” of the Abrahamic promise as Isaac. Though the human experience can involve disparate loyalties and deception, God remains at work in the world to uphold covenantal promises.