Genesis 48:8-20:Sovereign choice.

“8 When Israel saw the sons of Joseph, he asked, ‘Who are these?’‘They are the sons God has given me here,’ Joseph said to his father.Then Israel said, ‘Bring them to me so that I may bless them.’10 Now Israel’s eyes were failing because of old age, and he could hardly see. So Joseph brought his sons close to him, and his father kissed them and embraced them.11 Israel said to Joseph, ‘I never expected to see your face again, and now God has allowed me to see your children too.’12 Then Joseph removed them from Israel’s knees and bowed down with his face to the ground. 13 And Joseph took both of them, Ephraim on his right towards Israel’s left hand and Manasseh on his left towards Israel’s right hand, and brought them close to him. 14 But Israel reached out his right hand and put it on Ephraim’s head, though he was the younger, and crossing his arms, he put his left hand on Manasseh’s head, even though Manasseh was the firstborn.15 Then he blessed Joseph and said,‘May the God before whom my fathers Abraham and Isaac walked faithfully,the God who has been my shepherd  all my life to this day,16 the Angel who has delivered me from all ha   – may he bless these boys.May they be called by my name and the names of my fathers Abraham and Isaac,and may they increase greatly on the earth.’17 When Joseph saw his father placing his right hand on Ephraim’s head he was displeased; so he took hold of his father’s hand to move it from Ephraim’s head to Manasseh’s head. 18 Joseph said to him, ‘No, my father, this one is the firstborn; put your right hand on his head.’19 But his father refused and said, ‘I know, my son, I know. He too will become a people, and he too will become great. Nevertheless, his younger brother will be greater than he, and his descendants will become a group of nations.’ 20 He blessed them that day and said,‘In your[a] name will Israel pronounce this blessing: “May God make you like Ephraim and Manasseh.”’So he put Ephraim ahead of Manasseh.” NIV

The right hand was regarded to be the place of honour. As Manasseh was the firstborn, Joseph would have expected him to be given the special blessing. But in a prophetic action, Jacob, who could hardly see, crossed his hands and gave this to Ephraim. Generations later, Manasseh and Ephraim would become two of Israel’s most important tribes. But in giving the primary blessing to Ephraim, Jacob foresaw that Ephraim’s descendants would be even greater than Manasseh’s – and this came to be.  In giving Ephraim the status of the oldest son, Jacob repeated a pattern we have seen earlier in Genesis, in which the younger brother gets the blessing that ‘by right’ was thought to belong to the older one (if you recall, Seth was chosen over Cain, Shem over Japheth, Isaac over Ishmael, and Jacob over Esau). This shows that God’s choices are not based on natural descent, or on anyone’s perceived ‘rights’ or ‘merits’, but rather on grace alone. He is Sovereign and He does as He pleases.

Tom Hale, in my view, comments helpfully:

‘Therefore should anyone of us seem for a period to be especially blessed or favoured by God, we must always remember that it has come about not by our own doing but rather by God’s grace (1 Corinthians 15:10).’ ‘The Applied Old Testament Commentary’, p.199