Mr. Ryrie’s notes have it that when Jacob deceived Isaac, Isaac being old and thinking that he was preparing to die, that Isaac went on to live another 43 years. It’s not obvious how he gets this and so here is how it’s done, first in text, then with a picture.

  1. Joseph was 39 when Jacob came to Egypt. Jacob was 130 (45:11 + 47:9)
  2. Jacob was 91 when Joseph was born (subtract 39 from both sides)
  3. Jacob had been in Padan Aram 14 years when Joseph was born (30:25 + 31:41)
  4. Jacob was 77 when he stole the blessing and left home (subtract 14 from 91)
  5. Isaac was 60 years old when Jacob was born (25:26)
  6. Isaac was 137 when Jacob stole the blessing (60 + 77)
  7. Isaac lived 43 more years to 180 (35:28)

In the picture, (click to see a larger view) just use the red horizontal arrows to align the columns and work forward from Jacob’s birth and backwards from Joseph in Egypt. Simple.