I will bless those who bless you, but the one who treats you lightly I must curse, so that all the families of the earth may receive blessing through you.
And your offspring shall possess the gate of his enemies, and through your offspring all nations on earth will be blessed, because you have obeyed me.
In Genesis 12, Isaac was yet to be born. In Genesis 22 Isaac has already been born. "Offspring" in Genesis 22 therefore links the promise of blessing to the nations explicitly to a future descendant from Abraham according to the Reformation Study Bible.
Throughout the Abraham narrative, a distinction is drawn between the patriarch's many descendants and a future descendant who will come from the unique family line that is traced throughout Genesis. The prophecy that this descendant shall possess the gate of his enemies (singular his) refers back to the initial promise in Genesis 3, which we already covered - that one of Eve's offspring will overcome the serpent.
The Messiah therefore will therefore be born from the line of Eve, and it is now narrowed to the line of Abraham, specifically through Isaac.
Even long before Jesus was born when Moses wrote Genesis, we can find clues of Jesus' genealogy:
We can already establish the line from Adam to Noah, Noah to Isaac. Elsewhere in Genesis, although not explicitly stated, a section of history only makes sense when we compare it with Jesus' genealogy.
In Genesis 37 the narrative of Joseph begins and is abruptly interrupted by a section on Judah. This section, Genesis 38, talks about Judah and Tamar and the twins that were born to her. One of the twins was called Perez. Genesis then continues in Genesis 39 to follow Joseph in Egypt.
What is the significance of Genesis 38? Judah surely had lots of other children? What's the point of interrupting Joseph to give us this "non-useful" information about Judah? Later in the Bible when we read Jesus' genealogy, we actually see that Jesus comes from the line of Judah, through Perez! Genesis was written 1450 BC to 1400 BC.
He is the one who will build a house for my Name, and I will establish the throne of his kingdom forever. I will be his father, and he will be my son. When he does wrong, I will punish him with a rod wielded by men, with floggings inflicted by human hands.
2 Samuel 7:13-14
The manner in which the punishment takes place indicates that the Messiah will have a human nature.
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