Why was Joseph already in Egypt for 12 years when Isaac died?
Joseph was already in Egypt for 12 years when Isaac died because his brothers sold him into slavery at age 17. By the time Isaac died at 180, Joseph was 29, meaning 12 years had passed since the sale. The context ties this to the coat of many colors incident.
Les explains this timing by tracing the patriarchal ages. Isaac was 60 when Jacob and Esau were born, so when Isaac dies at 180, the twins are 120. At that same point Joseph is 29, and he has already been in Egypt 12 years. The reason is that his brothers sold him into slavery when they took his coat of many colors, and Scripture notes Joseph was 17 at the time. Thus 17 plus 12 years equals 29, placing the sale well before Isaac's death. This fits the broader chronology of Jacob's return to Canaan, Rachel's death in childbirth with Benjamin, and Jacob's later years with Isaac in Beersheba.