I think there was a real sense in which Joseph had died to Jacob when he went to Egypt. He now was more Egyptian that Hebrew and that’s where his priorities in the life lay, even if he still had hope for return to Canaan one day. This fact probably helps us to understand a little of what is said and done next.
Read Genesis 48
Joseph hears that his father is ill. He takes his sons, Manasseh and Ephraim to see him , Jacob rallies a bit when he is told that his son is there (v1-2). He then reminds Joseph of his vision at Luz/Bethel and God’s promise to him (v3-4). He also states that he regards Joseph’s son as his own. I think this reflects what I’ve said above that Joseph had been lost to him and was now first and foremost an Egyptian. There is also perhaps something linked in to Rachel’s death. Perhaps he had hoped for more children from her (v5-7).
He is then told that Josephs sons are present. I suspect he needs things reporting as his sight fail. But there is also a semi liturgical call and response to the question “Who are these” and the answer. Confirmation that these are the ones given over to Jacob as sons. Jacob asks for them to be brought to him to be blessed. It does seem too that this is an early meeting with the grandchildren, so it is possible that this is early in Jacob’s time in Egypt. “Some time later” refers back to Jacob’s meeting with Pharoah (v8-11).
Throughout the blessing there is this ambiguity between blessing Joseph and blessing the boys. The lives of father and sons are once again bound up together. Joseph notices that his father has placed his right hand on the younger son, indicating the first born’s blessing. When he attempts to correct Jacob, his father insists that he knows what he is doing. The older will be blessed too but the greater share will fall on the younger (v19-20).
Finally, even in this later stage, he demonstrates that Joseph is favoured. His descendants will receive a greater share of the land and so the inheritance. Ephraim is treated as firstborn even though younger because Joseph is treated as firstborn though younger (v21-22).
Digging a little deeper
Jacob’s blessing of the younger son is intentional. It’s a reminder both that Joseph had been favoured above his elder siblings bot more importantly of his own experience of blessing and birthright despite Esau being older. More than that, there is the sense that this is God’s pattern throughout Scripture starting with Abel favoured rather than Cain and including Gideon and David to come. Jesus will tell a parable of a younger son who receives grace and favour that causes his older brother to envy him. This points to the way that Gentiles will be brought in like the younger prodigal.
A look at ourselves
We do well to recognize that God turns the expected on its end. He chooses the weak and foolish things of this world as Paul puts it. That’s why his grace is given to us.