Isaac lives to be 180 (35:28), and the twins are born when he is 60 (25:26). That means that they are 120 when Isaac dies. Jacob goes down to Egypt just ten years later when he is 130 years old (47:9). Thus, Isaac remains alive for the twenty years that Jacob is with Laban, for the decade that Jacob is in Canaan before Joseph is sold, and for the years that Joseph is in Potiphar’s house (when Jacob moves to Egypt, Joseph has already been in power for nine years [45:6] and he had spent several in prison [40:1; 41:1]).
