What does Genesis 48:15 mean?

On his deathbed, Jacob is giving his blessing to his sons before he dies (Genesis 48:1–12). Instead of beginning with his oldest son Reuben, he starts with Joseph's sons. In fact, he declares them to be his own sons with the legal standing of the firstborn of all his sons. In doing this, Jacob ensures that Joseph's family will get a double portion of the inheritance. More than that, Jacob appears to be giving to Joseph's sons Ephraim and Manasseh the primary blessing, the family blessing. Jacob places his hands on their heads as they apparently kneel before him. However, Jacob puts his right hand on the younger son's head and his left hand on the older one (Genesis 48:13–14), something that will concern Joseph (Genesis 48:17).

Jacob makes it clear that the blessing is a prayer. It is not a hope or a wish for good fortune. It is a prayer that carries the weight of God's own promises. God has blessed Jacob abundantly. He now prays for God to bless his offspring in the same way. As Jacob begins his prayer, he addresses God.

Jacob recognizes God as the same Lord who spoke with his ancestors Abraham and Isaac. They walked before Him, Jacob says, meaning that they lived out their lives under his watchful, protective eyes. Jacob acknowledges that God has been his lifelong shepherd, as well. The picture of God as a shepherd, guiding His people through their lives, will be repeated many times in the Bible. King David will capture the metaphor beautifully in Psalm 23. Like Jacob, David will also be a shepherd. Later, Jesus will become known as the Great Shepherd of all who trust in Him (Hebrews 13:20).