Answer
There are two historically significant men named Manasseh in the Bible. King Manasseh, the son of King Hezekiah; and Manasseh, Joseph’s firstborn son. This article will deal with Joseph’s son. Joseph, Jacob’s eleventh son, was sold into slavery and, through the providence of God, ended up as the vizier of Egypt. In that land, he married Asenath, daughter of Potiphera, priest of On (Genesis 41:50). Asenath was the mother of Manasseh.
Manasseh’s name literally means “making forgetful”; Joseph said he chose that name “because God has made me forget all my trouble and all my father’s household” (Genesis 41:51). Joseph had a new life in Egypt and a new family.
Joseph and Asenath had a second son, Ephraim. Later, Joseph’s father, Jacob, and Joseph’s brothers and their families moved to Egypt to escape a famine. When Jacob was about to die, Joseph brought his sons to him for a patriarchal blessing. Jacob basically adopted the boys as his own sons (Genesis 48:5) so that they would share in his inheritance. Manasseh and Ephraim are among the twelve tribes of Israel that inherited territory in the Promised Land.
Joseph intended for Jacob to bless Manasseh more than Ephraim, since Manasseh was the firstborn and the customary recipient of the birthright. However, Jacob chose to give Ephraim the greater blessing—even though Joseph objected. Jacob said, “[Manasseh] 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” (Genesis 48:19). These words came to pass much later, when Moses took a census of all the children of Israel. Manasseh had 32,200 descendants who were age 20 and over and able to go to war, and Ephraim had 40,500 (Numbers 1:32–35). From then on, the tribe of Ephraim, the younger, is almost always listed before that of Manasseh, the older (see Numbers 2:18–20).