Genesis 48

1 Some time after Joseph had promised to bury his father in Canaan, Israel became very sick. Joseph took his two sons with him to receive the blessing of his father. Joseph and the rest of his brothers knew that Joseph would receive the blessing. He was the first born son of Israel's favorite wife (who was also indented to be his first wife). Joseph was also his favorite son. Joseph also wanted it to be clear that the blessing was to be with his children as well.
2 Good news can give us strength, even when we feel weak.
5 Israel was adopting Joseph's two sons as his own. When a Hebrew adopted a son or daughter, the child would be considered fully equal with any natural son or daughter.
8 Israel could not see well, and didn't recognize the young men as the sons he had just adopted.
11 God had reversed Israel's circumstances even beyond what he had could not even hope for.
12 Joseph showed great respect for his father, and is here recognizing him as the political and religious head of the household.
13 Now Joseph placed his sons in the "appropriate order" to receive the blessing. The oldest son was placed on the right-hand side, which is considered to be the more honored side in Hebrew society.
14 But God does not always do things in the way that seems "appropriate" to people. Israel is deliberately giving the younger son the better blessing by placing his right hand on his head.
15 Israel is blessing Joseph in the sense that he is blessing Joseph and all of his descendents.
16 This means that Joseph's descendents were to be known as God's children.
18 This would have been very unusual for a son to attempt to correct his father in such a matter as this.
19 Joseph should not have been surprised or dismayed that God did not choose his oldest son to receive the better blessing. After all, Israel received the blessing and the birthright even though he was younger than his twin brother was. Likewise, Joseph was second youngest of his brothers, and yet received the blessing. In many other passages of scripture we see God not choosing the best, brightest, or most popular people, places, or things to work through.What may not be clear is exactly how this all worked out. At the time of the Exodus, neither tribe had the most numbers. Upon division of the Promised Land, Manasseh ended up with the largest land area (divided between East and West Manasseh). Perhaps this blessing refers to the time when Israel was in Egypt. Later the blessing would pass to the tribe of Judah.
21 God would be with Joseph. When Joseph died, he was also to be returned to the land of Canaan. This would not happen until the Exodus.
22 Joseph was to receive the birthright as well as the blessing. The birthright meant that he would receive twice as much of the inheritance as the rest of his brothers.