What does Genesis 50:26 mean?

Nearing death, Joseph, has urgently communicated two messages to the "sons of Israel." This probably means the heads of the tribes, since Joseph is well over a hundred years old (Genesis 50:22), and was the second-youngest of his brothers.. The older brothers, themselves, have most likely passed away by now. First, he reminds them their people are not meant to live in Egypt forever. God will visit them when the time is right and take them to Canaan to give it to them (Genesis 17:5–8). This is as God promised Abraham, Isaac, and Jacob (Genesis 50:24). Second, Joseph made them swear to take his remains with them to Canaan to bury him there (Genesis 50:25).

Now Joseph dies at the age of 110. It is said to be a good, long life, though lifespans are rapidly shrinking across the book of Genesis. The very early patriarchs, up through Noah, lived for centuries (Genesis 9:29), but after the flood those lifespans regularly decrease. Abraham lived to be 175 (Genesis 25:7), Isaac 187 (Genesis 35:28), and Jacob 147 (Genesis 47:28). After Joseph's death, very few people will be said to live beyond 120. Long life—relative to those changes—will continue to be seen as evidence of God's blessing for right living (Deuteronomy 5:16).

Joseph and his father Jacob are the only two people in the Old Testament described as being embalmed. Egyptian embalming—often called "mummification"—was not always reserved for the highly honored and wealthy in Egyptian society. However, just as is the case today, wealth and status were associated with more extensive preparations. In part, this was due to Egyptian beliefs about transferring one's life through the physical body into the afterlife. Joseph, as second only to Pharaoh, would have easily qualified for the greatest possible care. Mummification was an extensive process that involved removal of the brain and internal organs, insertion of spices, and soaking of the body in special fluids before wrapping the corpse in linen bandages.

Instead of placing Joseph's corpse in an ornate tomb or temple, however, it was placed in a coffin. Apparently, this container was kept in the possession of the Israelites in Goshen for the next 400 years: until the time of Moses. When the exodus finally comes, Moses will take Joseph's remains with him for the journey to the Promised Land (Exodus 13:19).