When Isaac Died

In our Bible story today (Genesis 46), Jacob traveled to Egypt and met the pharaoh. He said he was pretty young -- only 130 -- not nearly as old as his forefathers lived to be. This is probably tremendously unimportant, but I got to wondering about the math.

Isaac's twins were born when he was 60. He lived to be 180. That means Jacob was 120 when his dad died. That means Isaac died 10 years before the children of Israel went to live in Goshen. Since Simeon spent two years in jail before Jacob allowed the fellows to return to Egypt with Benjamin, and since there were seven years of plenty before the famine, and since Joseph spent two years in prison prior to the butler remembering about his ability to tell dreams, that means Isaac died sometime after Joseph had interpreted the dreams for the butler and the baker.

That means Isaac was still alive when Joseph disappeared and while impenitence was reigning in the brothers' hearts. (I never noticed that before because the sequence of the stories is not chronological: the Bible wraps up Isaac's life-story before delving into Joseph's.)